Add scaling note to STC/LTC tunes

xu-shawn · vondele · commit adfddd2c984f · 2025-09-02T20:42:03.000+02:00
It has been repeatedly shown that such tunes are suspectible to become anti-scaling. Below are some recent examples: 2e91a86 d11f49b Passed STC: LLR: 2.95 (-2.94,2.94) <0.00,2.00> Total: 32448 W: 8651 L: 8342 D: 15455 Ptnml(0-2): 81, 3695, 8408, 3914, 126 https://tests.stockfishchess.org/tests/view/6899489b0049e8ccef9d64ad Passed LTC: LLR: 2.95 (-2.94,2.94) <0.50,2.50> Total: 73854 W: 19042 L: 18649 D: 36163 Ptnml(0-2): 37, 7908, 20659, 8271, 52 https://tests.stockfishchess.org/tests/view/689abbe7fd8719b088c8d514 Revert VVLTC with STC bound: LLR: 2.95 (-2.94,2.94) <0.00,2.00> Total: 53802 W: 14030 L: 13740 D: 26032 Ptnml(0-2): 5, 4924, 16754, 5212, 6 https://tests.stockfishchess.org/tests/view/68a9a9f575da51a345a5a675 Revert VVLTC with LTC bound: LLR: 2.94 (-2.94,2.94) <0.50,2.50> Total: 53658 W: 14022 L: 13699 D: 25937 Ptnml(0-2): 3, 4894, 16712, 5217, 3 https://tests.stockfishchess.org/tests/view/68a8d2b2b6fb3300203bca77 https://tests.stockfishchess.org/tests/view/688cf38bf17748b4d23c8057 https://tests.stockfishchess.org/tests/view/6890bc7792fcad741b804a19 Passed LTC: LLR: 2.94 (-2.94,2.94) <0.50,2.50> Total: 74928 W: 19466 L: 19071 D: 36391 Ptnml(0-2): 37, 8048, 20901, 8439, 39 Failed Non-regression VLTC: LLR: -2.94 (-2.94,2.94) <-1.75,0.25> Total: 57704 W: 14643 L: 14928 D: 28133 Ptnml(0-2): 5, 5925, 17280, 5634, 8 https://tests.stockfishchess.org/tests/view/6890bc7792fcad741b804a19 (Note that an STC-tuned version passed non-regression, but was shortly simplified) #6040 Passed STC: LLR: 2.93 (-2.94,2.94) <0.00,2.00> Total: 27776 W: 7352 L: 7054 D: 13370 Ptnml(0-2): 68, 3126, 7221, 3386, 87 https://tests.stockfishchess.org/tests/view/680ec0f83629b02d74b1605b Passed LTC: LLR: 2.94 (-2.94,2.94) <0.50,2.50> Total: 161304 W: 41432 L: 40864 D: 79008 Ptnml(0-2): 61, 17305, 45357, 17863, 66 https://tests.stockfishchess.org/tests/view/680ec7f93629b02d74b16084 Failed Non-regression VVLTC: LLR: -2.94 (-2.94,2.94) <-1.75,0.25> Total: 313466 W: 80573 L: 81089 D: 151804 Ptnml(0-2): 38, 29689, 97782, 29199, 25 https://tests.stockfishchess.org/tests/view/6810d0533629b02d74b16756 #5907 #5887 Passed LTC with STC bounds: https://tests.stockfishchess.org/tests/view/67b115dd6c6b9e172ad1592f LLR: 2.94 (-2.94,2.94) <0.00,2.00> Total: 75756 W: 19393 L: 19044 D: 37319 Ptnml(0-2): 60, 8251, 20913, 8588, 66 Passed LTC with LTC bounds: https://tests.stockfishchess.org/tests/view/67af5f5d6c6b9e172ad15765 LLR: 2.94 (-2.94,2.94) <0.50,2.50> Total: 108126 W: 27880 L: 27412 D: 52834 Ptnml(0-2): 85, 11786, 29866, 12228, 98 Revert VVLTC w/ STC bounds: LLR: 2.94 (-2.94,2.94) <0.00,2.00> Total: 56342 W: 14536 L: 14246 D: 27560 Ptnml(0-2): 7, 5061, 17741, 5359, 3 https://tests.stockfishchess.org/tests/view/67be4f8ad8d5c2c657c52d10 Revert VVLTC w/ LTC bounds: LLR: 2.94 (-2.94,2.94) <0.50,2.50> Total: 66562 W: 17364 L: 17016 D: 32182 Ptnml(0-2): 3, 6145, 20637, 6493, 3 https://tests.stockfishchess.org/tests/view/67bcd25ff6b602bd7222ea40 closes #6284 no functional change
diff --git a/src/search.cpp b/src/search.cpp
@@ -72,6 +72,9 @@ using SearchedList                  = ValueList<Move, SEARCHEDLIST_CAPACITY>;
 // so changing them or adding conditions that are similar requires
 // tests at these types of time controls.
 
+// (*Scaler) All tuned parameters at time controls shorter than
+// optimized for require verifications at longer time controls
+
 int correction_value(const Worker& w, const Position& pos, const Stack* const ss) {
     const Color us    = pos.side_to_move();
     const auto  m     = (ss - 1)->currentMove;
