This patch is a cleanup/simplification of king flank defenders patch,
removing king flanks attacks linear dependance in kingdanger. Result
of experiments with quadratic kingflank defenders scaling. Rebased on
the latest master.
passed STC
http://tests.stockfishchess.org/tests/view/
5ddc2b99e0b4af579302bacf
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 19660 W: 4309 L: 4184 D: 11167
passed LTC
http://tests.stockfishchess.org/tests/view/
5ddc3168e0b4af579302bade
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 24362 W: 3974 L: 3859 D: 16529
Closes https://github.com/official-stockfish/Stockfish/pull/2428
bench
5742013
+ 148 * popcount(unsafeChecks)
+ 98 * popcount(pos.blockers_for_king(Us))
+ 69 * kingAttacksCount[Them]
- + 4 * (kingFlankAttack - kingFlankDefense)
+ 3 * kingFlankAttack * kingFlankAttack / 8
+ mg_value(mobility[Them] - mobility[Us])
- 873 * !pos.count<QUEEN>(Them)
- 100 * bool(attackedBy[Us][KNIGHT] & attackedBy[Us][KING])
- 6 * mg_value(score) / 8
- - 7;
+ - 4 * kingFlankDefense
+ + 37;
// Transform the kingDanger units into a Score, and subtract it from the evaluation
if (kingDanger > 100)