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VoyagerOneandJoost VandeVondele c7118fb46d Simply do full sort on captures. 
STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 42712 W: 11413 L: 11203 D: 20096
Ptnml(0-2): 145, 4661, 11544, 4851, 155
https://tests.stockfishchess.org/tests/view/6384df57d2b9c924c4c53900

LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 239072 W: 64065 L: 64067 D: 110940
Ptnml(0-2): 106, 23735, 71859, 23727, 109
https://tests.stockfishchess.org/tests/view/63851120d2b9c924c4c541ee

closes https://github.com/official-stockfish/Stockfish/pull/4249

Bench: 3467381
 2022-12-02 20:05:50 +01:00
VoyagerOneandJoost VandeVondele 6a6faac04d Remove PvNode Parameter for cutoff LMR 
STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 198520 W: 52673 L: 52632 D: 93215
Ptnml(0-2): 645, 22241, 53499, 22178, 697
https://tests.stockfishchess.org/tests/view/63746e8f9849fa7a36a6698f

LTC:
LLR: 2.97 (-2.94,2.94) <-1.75,0.25>
Total: 253568 W: 67487 L: 67501 D: 118580
Ptnml(0-2): 109, 25222, 76141, 25198, 114
https://tests.stockfishchess.org/tests/view/63839859d2b9c924c4c4feb7

closes https://github.com/official-stockfish/Stockfish/pull/4248

Bench: 3733322
 2022-12-02 20:03:49 +01:00
VoyagerOneandJoost VandeVondele 85ae65db1d Skip full depth search in LMR depending on depth 
dynamically adjust newDepth, and skip full depth search if newDepth doesn't exceed the previous search depth.
This affects the used newDepth for future searches, and influences the stat bonus for the move.

Passed STC:
https://tests.stockfishchess.org/tests/view/63795500aa34433735bc1cfe
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 112776 W: 30082 L: 29663 D: 53031
Ptnml(0-2): 352, 12453, 30423, 12744, 416

Passed LTC:
https://tests.stockfishchess.org/tests/view/6379ea39aa34433735bc2f9b
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 83576 W: 22559 L: 22169 D: 38848
Ptnml(0-2): 38, 8011, 25303, 8395, 41

closes https://github.com/official-stockfish/Stockfish/pull/4240

Bench: 4390318
 2022-11-23 21:25:14 +01:00
VoyagerOneandJoost VandeVondele 41c6a74d37 Simplification away Cutoff Reset 
STC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 150184 W: 39913 L: 39819 D: 70452
Ptnml(0-2): 493, 16796, 40474, 16782, 547
https://tests.stockfishchess.org/tests/view/63723e9e54d69a2f33911d3c

LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 58880 W: 15890 L: 15717 D: 27273
Ptnml(0-2): 35, 5765, 17659, 5954, 27
https://tests.stockfishchess.org/tests/view/6373baf49849fa7a36a65427

closes https://github.com/official-stockfish/Stockfish/pull/4231

Bench: 4035152
 2022-11-19 09:29:04 +01:00
VoyagerOneandJoost VandeVondele ad357e147a CMH Pruning Tweak 
Tweak pruning formula by adding up CMH values.

STC:
LLR: 2.94 (-2.94,2.94) <-0.50,2.50>
Total: 14608 W: 3837 L: 3641 D: 7130
Ptnml(0-2): 27, 1681, 3723, 1815, 58
https://tests.stockfishchess.org/tests/view/612792f362d20cf82b5ad156

LTC:
LLR: 2.94 (-2.94,2.94) <0.50,3.50>
Total: 53520 W: 13580 L: 13276 D: 26664
Ptnml(0-2): 28, 5610, 15183, 5908, 31
https://tests.stockfishchess.org/tests/view/6127d27062d20cf82b5ad191

closes https://github.com/official-stockfish/Stockfish/pull/3682

Bench: 5186641
 2021-08-27 21:41:32 +02:00
VoyagerOneandJoost VandeVondele a1a83f3869 SEE simplification 
Simplified SEE formula by removing std::min. Should also be easier to tune.

STC:
LLR: 2.95 (-2.94,2.94) <-2.50,0.50>
Total: 22656 W: 1836 L: 1729 D: 19091
Ptnml(0-2): 54, 1426, 8267, 1521, 60
https://tests.stockfishchess.org/tests/view/610ae62f2a8a49ac5be79449

LTC:
LLR: 2.93 (-2.94,2.94) <-2.50,0.50>
Total: 26248 W: 806 L: 744 D: 24698
Ptnml(0-2): 6, 668, 11715, 728, 7
https://tests.stockfishchess.org/tests/view/610b17ad2a8a49ac5be79466

closes https://github.com/official-stockfish/Stockfish/pull/3643

bench:  4915145
 2021-08-05 16:32:07 +02:00
VoyagerOneandJoost VandeVondele 31ebd918ea Futile pruning simplification 
Remove CMH conditions in futile pruning.

STC:
LLR: 2.94 (-2.94,2.94) <-2.50,0.50>
Total: 93520 W: 7165 L: 7138 D: 79217
Ptnml(0-2): 222, 5923, 34427, 5982, 206
https://tests.stockfishchess.org/tests/view/61083104e50a153c346ef8df

LTC:
LLR: 2.93 (-2.94,2.94) <-2.50,0.50>
Total: 59072 W: 1746 L: 1706 D: 55620
Ptnml(0-2): 13, 1562, 26353, 1588, 20
https://tests.stockfishchess.org/tests/view/610894f2e50a153c346ef913

closes https://github.com/official-stockfish/Stockfish/pull/3638

Bench: 5229673
 2021-08-05 08:44:38 +02:00
VoyagerOneandJoost VandeVondele a0fca67da4 CMH Pruning Tweak 
replace CounterMovePruneThreshold by a depth dependent threshold

STC:
LLR: 2.94 (-2.94,2.94) <-0.50,2.50>
Total: 35512 W: 2718 L: 2552 D: 30242
Ptnml(0-2): 66, 2138, 13194, 2280, 78
https://tests.stockfishchess.org/tests/view/6104442fafad2da4f4ae3b94

LTC:
LLR: 2.96 (-2.94,2.94) <0.50,3.50>
Total: 36536 W: 1150 L: 1019 D: 34367
Ptnml(0-2): 10, 920, 16278, 1049, 11
https://tests.stockfishchess.org/tests/view/6104b033afad2da4f4ae3bbc

closes https://github.com/official-stockfish/Stockfish/pull/3636

Bench: 5848718
 2021-07-31 15:29:19 +02:00
VoyagerOneandJoost VandeVondele 36f8d3806b Don't save excluded move eval in TT 
STC:
LLR: 2.93 (-2.94,2.94) <-0.50,2.50>
Total: 17544 W: 1384 L: 1236 D: 14924
Ptnml(0-2): 37, 1031, 6499, 1157, 48
https://tests.stockfishchess.org/tests/view/60ec8d9bd1189bed71812999

LTC:
LLR: 2.95 (-2.94,2.94) <0.50,3.50>
Total: 26136 W: 823 L: 707 D: 24606
Ptnml(0-2): 6, 643, 11656, 755, 8
https://tests.stockfishchess.org/tests/view/60ecb11ed1189bed718129ba

closes https://github.com/official-stockfish/Stockfish/pull/3614

Bench: 5505251
 2021-07-13 17:35:20 +02:00
VoyagerOneandJoost VandeVondele 6174a37a37 Remove Stat Reset at beta cutoff 
STC:
LLR: 2.93 (-2.94,2.94) <-2.50,0.50>
Total: 63936 W: 5350 L: 5288 D: 53298
Ptnml(0-2): 184, 4295, 22954, 4345, 190
https://tests.stockfishchess.org/tests/view/60affb4c12066fd299795c64

LTC:
LLR: 2.96 (-2.94,2.94) <-2.50,0.50>
Total: 35856 W: 1201 L: 1142 D: 33513
Ptnml(0-2): 7, 1031, 15795, 1086, 9
https://tests.stockfishchess.org/tests/view/60b0537812066fd299795cc6

closes https://github.com/official-stockfish/Stockfish/pull/3505

bench: 3831936
 2021-05-28 20:16:11 +02:00
VoyagerOneandJoost VandeVondele 2a69611509 LMR Simplification 
remove reduction at non-check cut nodes for second move at low depths

STC:
LLR: 2.95 (-2.94,2.94) {-1.25,0.25}
Total: 61712 W: 6594 L: 6543 D: 48575
Ptnml(0-2): 293, 5085, 20082, 5070, 326
https://tests.stockfishchess.org/tests/view/5f5007d6ba100690c5cc5ea9

LTC:
LLR: 2.94 (-2.94,2.94) {-0.75,0.25}
Total: 57544 W: 2983 L: 2925 D: 51636
Ptnml(0-2): 47, 2568, 23495, 2604, 58
https://tests.stockfishchess.org/tests/view/5f50c597ba100690c5cc5ef7

closes https://github.com/official-stockfish/Stockfish/pull/3103

Bench: 3952302
 2020-09-04 08:00:45 +02:00
VoyagerOneandJoost VandeVondele a8bbaa1795 LMR Root Node Simplification 
Simplify LMR at Root node

STC:
LLR: 2.94 (-2.94,2.94) {-1.25,0.25}
Total: 71520 W: 7649 L: 7614 D: 56257
Ptnml(0-2): 346, 5845, 23349, 5868, 352
https://tests.stockfishchess.org/tests/view/5f4be8c0ba100690c5cc5cbb

LTC:
LLR: 2.95 (-2.94,2.94) {-0.75,0.25}
Total: 74832 W: 3997 L: 3948 D: 66887
Ptnml(0-2): 77, 3422, 30362, 3485, 70
https://tests.stockfishchess.org/tests/view/5f4c603eba100690c5cc5d0e

closes https://github.com/official-stockfish/Stockfish/pull/3091

Bench: 3624569
 2020-09-01 09:31:40 +02:00
VoyagerOneandJoost VandeVondele 9b5b9ec9a6 QS Pruning Simplification 
Remove depth dependence in QS pruning

STC:
LLR: 2.95 (-2.94,2.94) {-1.25,0.25}
Total: 40536 W: 4442 L: 4358 D: 31736
Ptnml(0-2): 209, 3330, 13118, 3390, 221
https://tests.stockfishchess.org/tests/view/5f49035b3def6407861152f9

LTC:
LLR: 2.95 (-2.94,2.94) {-0.75,0.25}
Total: 97104 W: 5164 L: 5130 D: 86810
Ptnml(0-2): 103, 4478, 39377, 4470, 124
https://tests.stockfishchess.org/tests/view/5f4939d53def640786115322

closes https://github.com/official-stockfish/Stockfish/pull/3077

Bench: 3865238
 2020-08-30 14:17:23 +02:00
VoyagerOneandJoost VandeVondele 242a7d9fea Simplify MCP in QS 
Simplify moveCount pruning in QS by removing depth dependency.

STC
LLR: 2.94 (-2.94,2.94) {-1.25,0.25}
Total: 42960 W: 4741 L: 4661 D: 33558
Ptnml(0-2): 218, 3574, 13804, 3678, 206
https://tests.stockfishchess.org/tests/view/5f42e3f75089a564a10d8493

LTC
LLR: 2.94 (-2.94,2.94) {-0.75,0.25}
Total: 66672 W: 3563 L: 3508 D: 59601
Ptnml(0-2): 71, 3064, 26996, 3149, 56
https://tests.stockfishchess.org/tests/view/5f4353285089a564a10d84d0

closes https://github.com/official-stockfish/Stockfish/pull/3067

Bench: 4074430
 2020-08-26 07:19:35 +02:00
VoyagerOneandJoost VandeVondele 95b8f3f800 Remove Reduce Depth 
Remove Reduce Depth at PV nodes.

STC:
LLR: 2.94 (-2.94,2.94) {-1.25,0.25}
Total: 56760 W: 6299 L: 6236 D: 44225
Ptnml(0-2): 286, 4843, 18076, 4872, 303
https://tests.stockfishchess.org/tests/view/5f41356087a5c3c63d8f53c9

LTC:
LLR: 2.95 (-2.94,2.94) {-0.75,0.25}
Total: 17496 W: 954 L: 865 D: 15677
Ptnml(0-2): 13, 768, 7098, 855, 14
https://tests.stockfishchess.org/tests/view/5f41bb7687a5c3c63d8f53f9

closes https://github.com/official-stockfish/Stockfish/pull/3055

Bench: 3555051
 2020-08-26 07:16:50 +02:00
VoyagerOneandJoost VandeVondele 1c0b7bdf4f Remove history bonus from Eval 
STC:
LLR: 2.92 (-2.94,2.94) {-1.50,0.50}
Total: 26776 W: 2787 L: 2725 D: 21264
https://tests.stockfishchess.org/tests/view/5f39d6beb38d442594aabd9b

LTC:
LLR: 2.93 (-2.94,2.94) {-1.50,0.50}
Total: 12968 W: 635 L: 608 D: 11725
https://tests.stockfishchess.org/tests/view/5f39decfb38d442594aabda7

closes https://github.com/official-stockfish/Stockfish/pull/3019

Bench:  4335100
 2020-08-18 08:29:42 +02:00
VoyagerOneandStéphane Nicolet 472de897cb Current capture for Counter-Move history 
Use current capture to index the CMH table instead of prior capture.

STC:
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 61908 W: 13626 L: 13220 D: 35062
http://tests.stockfishchess.org/tests/view/5da8aa670ebc597ba8eda558

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 49057 W: 8071 L: 7765 D: 33221
http://tests.stockfishchess.org/tests/view/5da8e99d0ebc597ba8eda9ca

Closes https://github.com/official-stockfish/Stockfish/pull/2362

Bench: 4423737
 2019-10-18 17:05:23 +02:00
VoyagerOneandStéphane Nicolet 80d59eea39 Introduce separate counter-move tables for inCheck 
Enhance counter-move history table by adding a inCheck dimension. This doubles
the size of the table but provides more accurate move ordering.

STC: (yellow)
LLR: -2.94 (-2.94,2.94) [0.50,4.50]
Total: 36217 W: 7790 L: 7777 D: 20650
http://tests.stockfishchess.org/tests/view/5d9b9a290ebc5902b6d04fe0

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,3.50]
Total: 36665 W: 6063 L: 5788 D: 24814
http://tests.stockfishchess.org/tests/view/5d9b9fcc0ebc5902b6d05985

Closes https://github.com/official-stockfish/Stockfish/pull/2353

Bench: 4053577
 2019-10-09 15:22:16 +09:00
VoyagerOneandStéphane Nicolet 2e96c513ad Introduce separate counter-move tables for captures 
Enhance counter-move history table by adding a capture/no-capture dimension,
depending wether the previous move was a quiet move or a capture. This doubles
the size of the table but provides more accurate move ordering.

STC:
LLR: 2.95 (-2.94,2.94) [0.50,4.50]
Total: 79702 W: 17720 L: 17164 D: 44818
http://tests.stockfishchess.org/tests/view/5d97945e0ebc590c21aa724b

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,3.50]
Total: 29147 W: 4907 L: 4651 D: 19589
http://tests.stockfishchess.org/tests/view/5d97ccb90ebc590c21aa7bc0

Closes https://github.com/official-stockfish/Stockfish/pull/2344

Bench: 4131643
 2019-10-06 02:04:19 +02:00
VoyagerOneandStéphane Nicolet 0e295fee25 NMP Tweaks 
Tweak again the null move pruning preconditions.

STC:
LLR: 2.96 (-2.94,2.94) [0.50,4.50]
Total: 19675 W: 4430 L: 4169 D: 11076
http://tests.stockfishchess.org/tests/view/5d52bc0e0ebc5925cf108300

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,3.50]
Total: 73895 W: 12496 L: 12114 D: 49285
http://tests.stockfishchess.org/tests/view/5d52dcbc0ebc5925cf108552

Closes https://github.com/official-stockfish/Stockfish/pull/2268

Bench: 3690065
 2019-08-25 11:09:08 +02:00
VoyagerOneandStéphane Nicolet dc243a3c88 LMR Tweak 
Reset statScore to zero if negative and most stats shows >= 0

STC:
LLR: 2.95 (-2.94,2.94) [0.50,4.50]
Total: 23097 W: 5242 L: 4963 D: 12892
http://tests.stockfishchess.org/tests/view/5d31dd650ebc5925cf0e598f

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,3.50]
Total: 227597 W: 39013 L: 38191 D: 150393
http://tests.stockfishchess.org/tests/view/5d31fcdf0ebc5925cf0e5c13

Closes https://github.com/official-stockfish/Stockfish/pull/2252

Bench: 3242229
 2019-07-25 08:46:26 +02:00
VoyagerOneandStéphane Nicolet c83cbe42f3 Tweak capture scoring formula 
STC:
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 20556 W: 4685 L: 4438 D: 11433
http://tests.stockfishchess.org/tests/view/5d25d26e0ebc5925cf0d0b4a

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 14856 W: 2649 L: 2446 D: 9761
http://tests.stockfishchess.org/tests/view/5d25d8b20ebc5925cf0d0c6d

bench: 3206912
 2019-07-11 11:59:36 +02:00
VoyagerOneandStephane Nicolet 297c40291a QuietPick Speed-up 
Non-functional speedup: no need to generate, score, or sort quiet moves
if SkipQuiet is true. Thanks to @mstembera for his suggestion.

STC:
LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 27910 W: 6406 L: 6129 D: 15375
http://tests.stockfishchess.org/tests/view/5d07e0920ebc5925cf0a58a8

Closes https://github.com/official-stockfish/Stockfish/pull/2194

No functional change
 2019-06-20 16:22:45 +02:00
VoyagerOneandMarco Costalba 46ce245763 Simplify SEE Pruning (#2191) 
Simplify SEE Pruning
Note this should also be a speedup...
If givesCheck is extended we know (except for DC) that it will have a positive SEE. So this new logic will be triggered before doing another expensive SEE function.

STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 24429 W: 5484 L: 5368 D: 13577
http://tests.stockfishchess.org/tests/view/5cffbccd0ebc5925cf09a154

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 28428 W: 4873 L: 4765 D: 18790
http://tests.stockfishchess.org/tests/view/5d0015f60ebc5925cf09acb1

Bench: 3897263
 2019-06-14 19:59:17 +02:00
VoyagerOneandMarco Costalba a9cca5c953 No DC prune in QS (#2185) 
Don't prune discover checks in qSearch

STC:
LLR: 2.96 (-2.94,2.94) [0.50,4.50]
Total: 23176 W: 5320 L: 5039 D: 12817
http://tests.stockfishchess.org/tests/view/5cfbc9350ebc5925cf094ab3

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,3.50]
Total: 128428 W: 22222 L: 21679 D: 84527
http://tests.stockfishchess.org/tests/view/5cfbf0b70ebc5925cf094ebc

Bench: 3883245
 2019-06-10 00:26:47 +02:00
VoyagerOneandMarco Costalba 6ed81f09ff SEE Pruning Tweak (#2183) 
Don't SEE prune any check extensions

STC (yellow):
LLR: -2.96 (-2.94,2.94) [0.50,4.50]
Total: 129934 W: 29390 L: 28905 D: 71639
http://tests.stockfishchess.org/tests/view/5cf6b1a70ebc5925cf08dedb

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,3.50]
Total: 102115 W: 17692 L: 17224 D: 67199
http://tests.stockfishchess.org/tests/view/5cf830710ebc5925cf090331
 2019-06-09 14:27:50 +02:00
VoyagerOneandMarco Costalba aba906b734 Stat Score reset at rootNode - Bench: 3393330 (#2124) 
At rootNode reset great great grandchildren stat score i.e (ss + 4)->statScore = 0

STC: (yellow)
LLR: -2.96 (-2.94,2.94) [0.50,4.50]
Total: 256079 W: 57423 L: 56315 D: 142341
http://tests.stockfishchess.org/tests/view/5ccb0c420ebc5925cf03a6a5

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,3.50]
Total: 61550 W: 10611 L: 10260 D: 40679
http://tests.stockfishchess.org/tests/view/5ccbf9d00ebc5925cf03c487

Bench: 3393330
 2019-05-04 13:41:53 +02:00
VoyagerOneandStéphane Nicolet e8ffca3eb4 Tweak CMH pruning 
STC: (yellow)
LLR: -2.94 (-2.94,2.94) [0.00,5.00]
Total: 48919 W: 10625 L: 10517 D: 27777
http://tests.stockfishchess.org/tests/view/5c07e6a20ebc5902bcee7395

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 50360 W: 8424 L: 8102 D: 33834
http://tests.stockfishchess.org/tests/view/5c0812450ebc5902bcee76f4

Bench: 3775064
 2018-12-09 13:11:13 +01:00
VoyagerOneandStéphane Nicolet 7b4f9c37cb Simplify Killer Move Penalty 
STC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 20816 W: 4525 L: 4402 D: 11889
http://tests.stockfishchess.org/tests/view/5c017cb90ebc5902bcede5b4

LTC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 39287 W: 6401 L: 6309 D: 26577
http://tests.stockfishchess.org/tests/view/5c01825e0ebc5902bcede686

Bench: 3773021
 2018-12-06 14:40:08 +01:00
VoyagerOneandStéphane Nicolet 4111f36f45 Simplify Castle Extension 
Remove depth condition in castle extension, also don't extend if
Singular Extension and Check Extansion fail to extend.

STC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 42070 W: 9118 L: 9036 D: 23916
http://tests.stockfishchess.org/tests/view/5be899cc0ebc595e0ae32f07

LTC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 78278 W: 12490 L: 12458 D: 53330
http://tests.stockfishchess.org/tests/view/5be8ac420ebc595e0ae33010

Bench: 3611041
 2018-11-19 10:28:55 +01:00
VoyagerOneandStéphane Nicolet 3ac3b68540 Don't modify Eval with search stats at ttHits 
STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 28344 W: 6148 L: 6040 D: 16156
http://tests.stockfishchess.org/tests/view/5b7d6b4e0ebc5902bdbb1914

LTC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 41084 W: 6769 L: 6680 D: 27635
http://tests.stockfishchess.org/tests/view/5b7d7f5b0ebc5902bdbb1b85

Bench: 4457440
 2018-08-29 00:41:53 +02:00
VoyagerOneandStéphane Nicolet 96c3a1f2ec Mix search stats with evaluation 
Mix search stats with evaluation: if the opponent's move has a good historyStat,
then decrease the evaluation of the internal node a bit for the pruning decisions
during search.

STC;
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 72083 W: 15683 L: 15203 D: 41197
http://tests.stockfishchess.org/tests/view/5b74c3ea0ebc5902bdba7d41

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 29104 W: 4867 L: 4630 D: 19607
http://tests.stockfishchess.org/tests/view/5b7565000ebc5902bdba851b

Closes https://github.com/official-stockfish/Stockfish/pull/1738

Bench: 4514101

-----------

How to continue from there?

• the use of the previous stat score can probably be simplified in lines 587 and 716
• we could try to use a continuous bonus based on the previous stat score, instead
  of just a fixed offset of -10 when the opponent previous move was good.

----------

Comments by Stefan Geschwentner:

Interesting idea. Because only the eval in search is tweak this should only
influence the eval and static eval used at inner nodes, and not on the return
search value (which comes in the end from quiescence search), except through
saving in TT followed by a TT cutoff.

So essentialy this effects diverse pruning/reduction parts -- eval and static
eval  are lowered for good opponent moves:

• tt cutoff (ttValue)
• improving (static eval)
• more razoring (eval)
• less futility pruning (eval)
• less null move pruning (eval + static eval) (but with little more depth)
• more probcut (static eval)
• more move futility pruning (static eval)
 2018-08-17 11:40:29 +02:00
VoyagerOneandStéphane Nicolet 6184d2b2ac Simplify cmh pruning 
Simplify cmh pruning by removing PvNode exception

STC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 9935 W: 2330 L: 2184 D: 5421
http://tests.stockfishchess.org/tests/view/5b587dc00ebc5902bdb88424

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 20635 W: 3585 L: 3464 D: 13586
http://tests.stockfishchess.org/tests/view/5b58910a0ebc5902bdb885b9

Closes https://github.com/official-stockfish/Stockfish/pull/1711

Bench: 4905530
 2018-07-27 16:23:45 +02:00
VoyagerOneandStéphane Nicolet 6e36860554 CounterMove History Pruning Tweak 
STC: (Yellow)
LLR: -2.96 (-2.94,2.94) [0.00,5.00]
Total: 40124 W: 8817 L: 8751 D: 22556
http://tests.stockfishchess.org/tests/view/5b5690180ebc5902bdb85c8a

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 21599 W: 3811 L: 3599 D: 14189
http://tests.stockfishchess.org/tests/view/5b5757010ebc5902bdb86b1f

Closes https://github.com/official-stockfish/Stockfish/pull/1697

Bench:  4794161
 2018-07-25 17:55:16 +02:00
VoyagerOneandStéphane Nicolet 3279655f12 Capture Stat Tweak 
Penalize capture moves that fail to create a cutoff even at quiet move cutoff.

STC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 19004 W: 4284 L: 4059 D: 10661
http://tests.stockfishchess.org/tests/view/5b3a7d4d0ebc5902b9ffb6ea

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 23100 W: 3981 L: 3765 D: 15354
http://tests.stockfishchess.org/tests/view/5b3aa4550ebc5902b9ffb8cf

Closes https://github.com/official-stockfish/Stockfish/pull/1664

Bench: 5232010
 2018-07-04 01:12:16 +02:00
VoyagerOneandStéphane Nicolet 231103d2cf Simplify capture bonus 
Simplify capture bonus by simply adding ONE_DEPTH instead of being
dependent on BestValue.

STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 24419 W: 4939 L: 4824 D: 14656
http://tests.stockfishchess.org/tests/view/5b16b2040ebc5963ba37e2a5

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 44560 W: 6524 L: 6438 D: 31598
http://tests.stockfishchess.org/tests/view/5b16ccc00ebc59214346d403

Closes https://github.com/official-stockfish/Stockfish/pull/1640

Bench: 4782637
 2018-06-06 09:58:34 +02:00
VoyagerOneandStéphane Nicolet 6b5d671cdc Simplify LMR for captures 
Simplify LMR for captures by removing capture's stat score logic for reduction.

STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 37068 W: 7462 L: 7370 D: 22236
http://tests.stockfishchess.org/tests/view/5b115bc30ebc591af58a6fd2

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 80061 W: 11706 L: 11671 D: 56684
http://tests.stockfishchess.org/tests/view/5b117f590ebc59033d2d5315

Closes https://github.com/official-stockfish/Stockfish/pull/1631

Bench: 4470519
 2018-06-05 09:58:10 +02:00
VoyagerOneandStéphane Nicolet 3d6995eae8 LMR Capture Tweak 
Increase capture reduction by comparing opponent's stat score

STC: (Yellow)
LLR: -2.96 (-2.94,2.94) [0.00,5.00]
Total: 92291 W: 18647 L: 18350 D: 55294
http://tests.stockfishchess.org/tests/view/5b04225e0ebc5914abc1291b

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 20176 W: 3061 L: 2868 D: 14247
http://tests.stockfishchess.org/tests/view/5b04bb3f0ebc5914abc129a3

How to continue?
• we could try a different value for the capture history threeshold

Closes https://github.com/official-stockfish/Stockfish/pull/1612

Bench: 5167159
 2018-05-24 19:06:24 +02:00
VoyagerOneandStéphane Nicolet 04407e35d6 Simply reset StatScore to zero at beta cutoff 
STC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 43154 W: 8706 L: 8625 D: 25823
http://tests.stockfishchess.org/tests/view/5b01a7660ebc5914abc1271d

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 48155 W: 7036 L: 6955 D: 34164
http://tests.stockfishchess.org/tests/view/5b01b2e50ebc5914abc1272c

Closes https://github.com/official-stockfish/Stockfish/pull/1608

Bench: 4484288
 2018-05-22 07:23:04 +02:00
VoyagerOneandStéphane Nicolet aacee91a5a Update search.cpp 
At PvNodes allow bonus for prior counter move that caused a fail low
for depth 1 and 2. Note : I did a speculative LTC on yellow STC patch
since history stats tend to be highly TC sensitive

STC (Yellow):
LLR: -2.96 (-2.94,2.94) [0.00,5.00]
Total: 64295 W: 13042 L: 12873 D: 38380
http://tests.stockfishchess.org/tests/view/5af507c80ebc5968e6524153

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 22407 W: 3413 L: 3211 D: 15783
http://tests.stockfishchess.org/tests/view/5af85dd40ebc591fdf408b87

Also use local variable excludedMove in NMP (marotear)

Bench:  5294316
 2018-05-14 06:52:48 +02:00
VoyagerOneandStéphane Nicolet b88374b14a Reset negative statScore on fail high 
STC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 9073 W: 1937 L: 1766 D: 5370

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 53530 W: 8139 L: 7823 D: 37568

Bench: 5170165
 2018-04-07 20:26:49 +02:00
VoyagerOneandStéphane Nicolet b2961aded6 Use quiescence search for Probcut 
Perform qsearch for the preliminary search in Probcut

Passed STC with sprt[-3..1] bounds:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 31090 W: 6386 L: 6283 D: 18421
http://tests.stockfishchess.org/tests/view/5aa598ed0ebc59029780ff9f

Passed LTC with sprt[0..4] bounds:
LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 104056 W: 15990 L: 15531 D: 72535
http://tests.stockfishchess.org/tests/view/5aa5b0f30ebc59029780ffa9

Closes https://github.com/official-stockfish/Stockfish/pull/1483

Bench: 5404567
 2018-03-13 08:21:11 +01:00
VoyagerOneandStéphane Nicolet b87308692a Do move-count pruning in probcut 
STC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 4928 W: 1163 L: 1007 D: 2758

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 20368 W: 3441 L: 3238 D: 13689
http://tests.stockfishchess.org/tests/view/5a98bea40ebc590297cc8e5d

Bench: 6361568
 2018-03-03 12:04:25 +01:00
VoyagerOneandMarco Costalba 87452f3a8c Capture Stat Simplification- Bench: 5363761 2017-11-10 12:12:58 +01:00
VoyagerOneandMarco Costalba 07b5a28a68 Decrease reduction for exact PV nodes 
STC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 59004 W: 10621 L: 10249 D: 38134

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 25801 W: 3306 L: 3108 D: 19387

Bench: 5742466
 2017-09-30 20:56:27 +02:00
VoyagerOneandMarco Costalba 3ac47c84d3 Streamlline reduction based on movecount 
Use MoveCount History only at quiet moves and simply reduce
reduction by one depth instead of increasing moveCount in formula.

STC:
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 27511 W: 5171 L: 4919 D: 17421

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 92337 W: 12135 L: 11748 D: 68454

Bench: 6351176
 2017-09-05 11:03:50 +02:00
VoyagerOneandMarco Costalba 7b4c9852e1 Adjust moveCount history only at LMR 
STC:
LLR: 3.32 (-2.94,2.94) [-3.00,1.00]
Total: 17584 W: 3277 L: 3131 D: 11176

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 26412 W: 3447 L: 3334 D: 19631

Bench: 5417521
 2017-08-31 08:53:37 +02:00
VoyagerOneandJoona Kiiski 722e1e0da6 Remove redundant if-statements 
No functional change

Closes #1173
 2017-07-27 02:14:18 -07:00
VoyagerOneandJoona Kiiski a6ae2d3a31 Simplify aspiration window 
Don't modify alpha window on fail-high

Bench: 5875983

Closes #1172
 2017-07-23 17:25:23 -07:00
VoyagerOneandJoona Kiiski 77342126d8 Increase reduction if tt-move is a capture 
The idea is that chances are the tt-move is best and will be difficult to raise alpha when playing a quiet move.

STC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 7582 W: 1415 L: 1259 D: 4908

LTC:
LLR: 2.97 (-2.94,2.94) [0.00,5.00]
Total: 59553 W: 7885 L: 7573 D: 44095

Bench: 5725676

Closes #1147
 2017-06-21 14:06:05 -07:00
VoyagerOneandJoona Kiiski 0149a4c3d6 Update Top CPU - Bench: 6599721 
Closes #1145
 2017-06-21 13:47:10 -07:00
VoyagerOneandJoona Kiiski 1d31065e1d Evasion Pruning Tweak 
Use moveCount to decide when to prune for evasion pruning

STC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 24476 W: 4518 L: 4289 D: 15669

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 18362 W: 2476 L: 2298 D: 13588

Bench: 6469989

Closes #1120
 2017-05-21 18:27:57 -07:00
VoyagerOneandJoona Kiiski a18c2c2c3f Don't do InCheck Pruning at the root of QS 
STC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 34603 W: 6441 L: 6167 D: 21995

LTC:
LLR: 2.97 (-2.94,2.94) [0.00,5.00]
Total: 24474 W: 3274 L: 3076 D: 18124

Bench: 5934421

Closes #1089
 2017-04-28 20:40:45 -07:00
VoyagerOneandJoona Kiiski 9d3ed9ed2e Move-Count Formula Tweak 
STC:
LLR: 3.18 (-2.94,2.94) [0.00,4.00]
Total: 55004 W: 10289 L: 9930 D: 34785

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 48184 W: 6401 L: 6128 D: 35655

Bench: 5960754
 2017-04-17 09:22:10 -07:00
VoyagerOneandJoona Kiiski 35b77b120e Standardize stat penalty 
STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 90631 W: 16325 L: 16323 D: 57983

LTC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 97679 W: 12779 L: 12759 D: 72141

Bench: 6340591

Closes #1053
 2017-04-07 17:02:31 -07:00
VoyagerOneandJoona Kiiski ebe021f6a5 Don't update TT at excluded move ply 
STC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 38906 W: 7125 L: 6835 D: 24946

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 28600 W: 3752 L: 3543 D: 21305

Bench:  6861050

Closes #1048
 2017-04-02 20:32:54 -07:00
VoyagerOneandJoona Kiiski 30c583204f Singular extension and check extension tweak 
If singular extension fails to trigger extension then don't consider check extension.

STC:
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 69428 W: 12663 L: 12271 D: 44494

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 44023 W: 5875 L: 5612 D: 32536

Bench: 6170444

Closes #1043
 2017-03-25 10:13:25 -07:00
VoyagerOneandJoona Kiiski 352bd6f5aa Skip quiet moves based on moveCount pruning threshold and history stats 
If we can moveCountPrune and next quiet move has negative stats,
then go directly to the next move stage (Bad_Captures).

Reduction formula is tweaked to compensate for the decrease in move count that is used in LMR.

STC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 6847 W: 1276 L: 1123 D: 4448

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 48687 W: 6503 L: 6226 D: 35958

Bench: 5919519

Closes #1036
 2017-03-18 15:44:49 -07:00
VoyagerOneandJoona Kiiski 3627348e2b Allow pruning advance pawn pushes if not near endgame 
STC:
LLR: -2.95 (-2.94,2.94) [0.00,5.00]
Total: 101088 W: 18016 L: 17717 D: 65355

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 61194 W: 8108 L: 7791 D: 45295

Bench: 5803228

Closes #1023
 2017-03-05 18:58:06 -08:00
VoyagerOneandJoona Kiiski 05cf45f2d1 Razor Simplification 
Remove code that restrict using tt-moves for razoring.

STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 67442 W: 12039 L: 11997 D: 43406

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 38541 W: 5044 L: 4947 D: 28550

Bench: 5667216

Closes #1002
 2017-02-18 22:50:37 -08:00
VoyagerOneandJoona Kiiski 83fb4547f6 search(): Move nullValue variable into local scope 
No functional change

Closes #1003
 2017-02-14 21:22:58 -08:00
VoyagerOneandJoona Kiiski 0553b46829 Simplify Queen Mobility 
STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 85997 W: 15550 L: 15540 D: 54907

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 25333 W: 3370 L: 3256 D: 18707

Bench: 6459194

Closes #991
 2017-02-05 15:40:30 -08:00
VoyagerOneandMarco Costalba fa24cc25a4 Simplify TT penalty stat (#980) 
STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 20251 W: 3692 L: 3570 D: 12989

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 16432 W: 2155 L: 2029 D: 12248

Bench: 5941174
 2017-01-29 08:54:58 +01:00
VoyagerOneandMarco Costalba 5254a6040c Penalty for a quiet ttMove that fails low 
Also the penalty/bonus function is misleading, we
should simply change it to stat_bonus(depth) for
bonus and -stat_bonus(depth+ ONE_PLY) for extra
penalty.

STC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 11656 W: 2183 L: 2008 D: 7465

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 11152 W: 1531 L: 1377 D: 8244

Bench: 6101931
 2017-01-28 09:32:07 +01:00
VoyagerOneandMarco Costalba 8c61bbda54 Another simplification for SEE pruning 
STC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 29310 W: 5225 L: 5118 D: 18967

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 128454 W: 16424 L: 16442 D: 95588

Bench: 4556848
 2016-12-17 08:37:58 +01:00
VoyagerOneandMarco Costalba b915fdc889 Reduction Simplification 
Simplify reduction formula by removing a parameter.

STC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 35798 W: 6368 L: 6272 D: 23158

LTC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 125375 W: 15827 L: 15839 D: 93709

Bench: 4735038
 2016-11-05 08:17:42 +01:00
VoyagerOneandMarco Costalba d4abf54247 Top CPU Contributors 
Give some well needed credit...

No functional change.
 2016-11-05 08:12:22 +01:00
VoyagerOneandMarco Costalba e77f38c431 History Stat Comparison 
Adjust LMR by comparing history stats
with opponent (prior ply).

STC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 27754 W: 5066 L: 4824 D: 17864

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 216596 W: 28157 L: 27343 D: 161096

Bench: 5437729
 2016-10-25 06:44:19 +02:00
VoyagerOneandMarco Costalba e27d3bb884 Use explicit logic for pruning 
Also a speedup since we don't need to recalculate SEE
for extensions...as it already determined to be positive.

Results for 12 tests for each version:

        Base      Test      Diff
Mean    2132395   2191002   -58607
StDev   128058    85917     134239
p-value: 0.669
speedup: 0.027

Non functional change.
 2016-10-18 08:53:51 +02:00
VoyagerOneandMarco Costalba ab26c61971 Allow inCheck pruning 
This is a bit tricky because we don't want
to prune the only legal evasions, even if
with negative SEE. So add an assert to avoid
this subtle bug to slip in later.

STC:
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 14140 W: 2625 L: 2421 D: 9094

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 11558 W: 1555 L: 1379 D: 8624

bench: 5256717
 2016-10-03 16:18:53 +02:00
VoyagerOneandMarco Costalba 95ad2b51b7 Tweak SEE margin in pruning conditions 
Use 35 * depth^2 to calculate see_margin.

STC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 22636 W: 4212 L: 3990 D: 14434

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 47241 W: 6314 L: 6041 D: 34886

The Movepick SEE is now dead code, retire it.

Bench: 5341477
 2016-09-14 15:38:38 +02:00
VoyagerOneandMarco Costalba 2731bbaf6b Remove condition on killers in history pruning 
Now allows main killer to be history prune.

STC:
LLR: 2.94 (-2.94,2.94) [-3.00,1.00]
Total: 15852 W: 2910 L: 2781 D: 10161

LTC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 56428 W: 7610 L: 7537 D: 41281

Bench: 8032058
 2016-08-30 09:09:55 +02:00
VoyagerOneandMarco Costalba 0b4f6e562b Refutation penalty on captures 
Apply refutation penalty for prior PV quiet move on captures

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 8208 W: 1153 L: 1008 D: 6047
http://tests.stockfishchess.org/tests/view/57bc5a9f0ebc59030fbe47b5

Only LTC because a very similar patch already passed STC + LTC

bench: 7038730
 2016-08-24 08:26:32 +02:00
VoyagerOneandMarco Costalba 5596492f6e Simplify IID 
STC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 30468 W: 5687 L: 5582 D: 19199
http://tests.stockfishchess.org/tests/view/57b1ddd80ebc591c761f63e2

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 87406 W: 11756 L: 11725 D: 63925
http://tests.stockfishchess.org/tests/view/57b212590ebc591c761f63f9

bench: 6554900
 2016-08-19 08:59:18 +02:00
VoyagerOneandMarco Costalba 8493c8c6b8 Do LMR on captures 
STC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 5361 W: 1086 L: 936 D: 3339
http://tests.stockfishchess.org/tests/view/57b31b0f0ebc591c761f643d

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 54694 W: 7591 L: 7287 D: 39816
http://tests.stockfishchess.org/tests/view/57b3442b0ebc591c761f6450

bench: 6881120
 2016-08-19 08:50:14 +02:00
VoyagerOneandMarco Costalba 7396c08b79 Use predicted depth for history pruning 
STC: (Yellow)
LLR: -2.96 (-2.94,2.94) [0.00,4.00]
Total: 69115 W: 12880 L: 12797 D: 43438

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 124163 W: 16923 L: 16442 D: 90798

Note: Note based off past experiments / patches... history pruning
is quite TC sensitive. I believe the reason for this TC dependency
is that the CMH/FMH is a very large table that takes time to fill
up with. In addition having more time for will increase the accuracy
of the stats' value.

Bench: 7351698
 2016-08-15 14:45:40 +02:00
VoyagerOneandMarco Costalba b3525fa9ea Use Color-From-To history stats to help sort moves 
STC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 33502 W: 6498 L: 6223 D: 20781
http://tests.stockfishchess.org/tests/view/578abb940ebc5972faa169e2

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 50782 W: 7124 L: 6832 D: 36826
http://tests.stockfishchess.org/tests/view/578b8e5d0ebc5972faa169fd

LTC: (Sanity test against latest master)
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 32759 W: 4600 L: 4370 D: 23789
http://tests.stockfishchess.org/tests/view/5798b7d30ebc591c761f5b72

bench: 6985912

P.S. Thanks @mstembera for rewriting my code to make it smp compatible. A BIG thank you!
 2016-08-02 09:17:14 +02:00
VoyagerOneandMarco Costalba 85924db496 Futility tweak 
Use a different margin for pruning child nodes.

STC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 16692 W: 3251 L: 3051 D: 10390
http://tests.stockfishchess.org/tests/view/579b95d10ebc591c761f5c03

LTC:
LLR: 2.97 (-2.94,2.94) [0.00,5.00]
Total: 24140 W: 3501 L: 3297 D: 17342
http://tests.stockfishchess.org/tests/view/579bb15d0ebc591c761f5c0b

Bench: 7927017
 2016-08-01 21:47:42 +02:00
VoyagerOneandMarco Costalba c94145b65c Comment out a redundant condition 
Take advantage that VALUE_NONE = 32002 to remove
the condition.

Commented out and not removed becuase it is tricky
to rely on the hidden value of VALUE_NONE and code
can break in case we change VALUE_NONE in the future.

No functional change.
 2016-06-24 08:26:39 +02:00
VoyagerOneandMarco Costalba 1c0c4db677 Simplify Check Extension 
STC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 32704 W: 6146 L: 6045 D: 20513

LTC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 146622 W: 19967 L: 20017 D: 106638

Bench: 8245662
 2016-06-18 08:32:25 +02:00
VoyagerOneandMarco Costalba 7d2a79f037 Stat Formula Tweak 
bonus = d * d + 2 * d - 2

STC:
LLR: 2.94 (-2.94,2.94) [0.00,4.00]
Total: 99444 W: 18274 L: 17778 D: 63392

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 89757 W: 12285 L: 11896 D: 65576

bench: 8276130
 2016-06-10 07:27:47 +02:00
VoyagerOneandMarco Costalba 7c5d724724 Tweak check extension condition 
There are two concepts with this patch:

Limit check extensions by using move count.
The idea is to limit search explosion.

Always extend check if the first move gives check.
The idea is to save expensive SEE calls, since the vast
majority of first move will have SEE value >= 0, also
first move may still be strong even if the SEE is negative.

STC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 16503 W: 3068 L: 2873 D: 10562

LTC:
LLR: 2.97 (-2.94,2.94) [0.00,5.00]
Total: 37202 W: 5261 L: 5014 D: 26927

bench: 8543366
 2016-06-10 07:15:56 +02:00
VoyagerOneandMarco Costalba 5f096e9bef Simplify Futility Pruning 
Don't update bestValue when futility pruning.

STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 21933 W: 4031 L: 3912 D: 13990

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 46225 W: 6115 L: 6028 D: 34082

Bench: 8450534
 2016-06-03 19:58:42 +02:00
VoyagerOneandMarco Costalba 5486911e01 Simplify History LMR Formula 
STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 41713 W: 7589 L: 7504 D: 26620

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 41353 W: 5484 L: 5391 D: 30478

Bench: 8946983
 2016-05-05 08:53:50 +02:00
VoyagerOneandJoona Kiiski e082112cfe Use FMHs to assist with LMR formula. 
STC:
LLR: 2.99 (-2.94,2.94) [0.00,5.00]
Total: 52232 W: 9654 L: 9304 D: 33274

LTC:
LLR: 2.97 (-2.94,2.94) [0.00,5.00]
Total: 115988 W: 15550 L: 15049 D: 85389

Bench: 7890808

Resolves #651
 2016-04-24 01:00:58 +01:00
VoyagerOneandJoona Kiiski 60590577f2 A small simplification in movepick.h 
No functional change

Resolves #597
 2016-03-14 20:54:49 -07:00
VoyagerOneandJoona Kiiski 45a309d92e Simplify Reduction Formula 
Formula now only contains one coefficient. Making it much easier to tune.

STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 187443 W: 34858 L: 35028 D: 117557

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 88329 W: 11982 L: 11953 D: 64394

Bench: 7521394

Resolves #591
 2016-02-28 13:31:25 +00:00
VoyagerOneandJoona Kiiski bfe9044ad9 History Stat Formula Simplification 
STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 67476 W: 12561 L: 12521 D: 42394

LTC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 111923 W: 15147 L: 15149 D: 81627

Bench: 8430465

Resolves #588
 2016-02-21 20:12:33 +00:00
VoyagerOneandJoona Kiiski 744ed85a4d Fix futility pruning bug 
PredictedDepth can be negative, causing the futility_margin to be negative.
It will be very difficult to tweak moveCount pruning and reduction formula, as they are tuned to prevent this behavior.

No functional change

Resolves #587
 2016-02-14 19:48:46 +00:00
VoyagerOneandJoona Kiiski ed72a1e9ba Remove killer move conditions from LMR 
STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 8459 W: 1619 L: 1477 D: 5363

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 32239 W: 4404 L: 4299 D: 23536

Bench: 7597031

Resolves #534
 2015-12-20 20:41:17 +00:00
VoyagerOneandJoona Kiiski 07e0741dfb History Pruning: Don't prune the main killer move. 
Also increased pruned depth to 4.

STC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 23380 W: 4581 L: 4350 D: 14449

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 28934 W: 4329 L: 4105 D: 20500

Bench: 8369743

Resolves #498
 2015-11-15 20:40:09 -08:00
VoyagerOneandJoona Kiiski aa242d2f84 New History Bonus Formula 
bonus = d^2 + d - 1

Bench: 8639247

Resolves #484
 2015-10-31 18:17:00 +00:00
VoyagerOneandMarco Costalba 4eca981e55 History pruning 
Prune moves with negative History
and CMH scores at low depth.

STC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 24182 W: 4672 L: 4439 D: 15071

LTC:
LLR: 2.97 (-2.94,2.94) [0.00,5.00]
Total: 12579 W: 1959 L: 1792 D: 8828

bench: 8907701
 2015-10-24 09:30:31 +02:00
VoyagerOneandGary Linscott 8fd34d7763 Combination of two ideas: 
Apply bonus for the prior CMH that caused a fail low.

Balance Stats: CMH and History bonuses are updated differently.
This eliminates the "fudge" factor weight when scoring moves. Also
eliminated discontinuity in the gravity history stat formula. (i.e. stat
scores will no longer inverse when depth exceeds 22)

STC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 21802 W: 4107 L: 3887 D: 13808

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 46036 W: 7046 L: 6756 D: 32234

Bench: 7677367
 2015-10-12 14:00:54 -07:00
VoyagerOneandGary Linscott a2410227cc PV refutation penalty 
Extra penalty for PV move in previous ply when it gets refuted.

STC:
LLR: 4.49 (-2.94,2.94) [-1.50,4.50]
Total: 41094 W: 7889 L: 7620 D: 25585

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,6.00]
Total: 12304 W: 1967 L: 1811 D: 8526

Bench: 8373608

Resolves #386
 2015-07-30 00:51:49 +08:00
VoyagerOneandJoona Kiiski 1d977aa79e LMR Simplification: Remove countermove condition 
Removed countermove condition for decreasing reduction.

LTC:
LLR: 3.01 (-2.94,2.94) [-3.00,1.00]
Total: 32410 W: 5092 L: 4986 D: 22332

STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 24450 W: 4632 L: 4517 D: 15301

Bench: 6943812

Resolves #378
 2015-07-15 20:21:14 +01:00
VoyagerOneandJoona Kiiski aa0dc16b75 CMH Fix: Exclude captures for TT move refutation penalty 
This will make sure we store only quiet moves for TT Penalty.

STC:
LLR: 2.96 (-2.94,2.94) [-1.50,4.50]
Total: 34748 W: 6617 L: 6420 D: 21711

LTC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 19975 W: 3259 L: 3137 D: 13579

Bench: 8063826

Resolves #373
 2015-07-04 14:22:41 +01:00
VoyagerOneandJoona Kiiski 7e9f776fca LMR Tweak: Decrease reduction if cmh>0 && history>0. 
STC:
LLR: 2.96 (-2.94,2.94) [-1.50,4.50]
Total: 9627 W: 1879 L: 1748 D: 6000

LTC:
LLR: 2.97 (-2.94,2.94) [0.00,6.00]
Total: 21543 W: 3433 L: 3234 D: 14876

Bench: 8646407

Resolves #370 #371
 2015-06-27 09:45:59 +01:00
VoyagerOneandJoona Kiiski b7063ef65b Change extra ply LMR condition to: cmh <= 0 && hist < 0 
Extra ply LMR condition is now cmh <= 0 && h < 0
Instead of cmh + h < 0

STC:
LLR: 2.96 (-2.94,2.94) [-1.50,4.50]
Total: 55210 W: 10812 L: 10557 D: 33841

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 13212 W: 2239 L: 2045 D: 8928

Bench: 8420865

Resolves #339
 2015-04-26 20:12:25 +01:00
VoyagerOneandJoona Kiiski 20e92895af Removed extra condition (history < 0) in LMR to help sync up with move ordering. 
LMR condition is now cmh+history<0
Instead of history<0 OR cmh+history<0

STC:
LLR: 2.96 (-2.94,2.94) [-3.00, 1.00]
Total: 26446 W: 5092 L: 4980 D: 16374

LTC:
LLR: 2.96 (-2.94,2.94) [-3.00, 1.00]
Total: 14129 W: 2340 L: 2209 D: 9580

Bench: 7815183

Resolves #331
 2015-04-12 20:05:59 +01:00