CorChess is a clone of Stockfish maintained for better performance on long time controls,
trying at least partially to fill the gap between regular tests and demands of correspondence players.

The first idea was to improve the following scalability of Stockfish 8
and from CorChess 2 I follow the idea from the following picture,
obtained by mathematical model for search tree efficiency.

IMPORTANT: CorChess 4 is most probably the final version of the engine.



Please contact me (ivan.ivec@gmail.com) about your experiences with CorChess.

I use strong 2moves book.

Regression tests between CorChess 2 and Stockfish 220821 (Ryzen 7 3700X - 1 core)
Hash Time control
in seconds		 #games Result Elo gain (± 2) Draw rate
1 MB 0.5+0.005 80000 12699-34076-33225 -95.15 41.5%
8 MB 5+0.05 25000 1293-3596-20111 -32.1 80.4%
64 MB 50+0.5 8000 98-244-7658 -6.34 95.7%
512 MB 500+5 2500 10-18-2472 -1.11 98.9%
900 MB 5000+50 800 0-0-800  0.0 100% 
Regression tests between CorChess 3 and Stockfish (Ryzen 7 3700X - 1 core)
Hash Time control in seconds #games Result SF version Elo gain / Draw rate
900 MB 1200+12 1080 3-3-1074 061221 0.0 / 99.4% 
128 MB 100+1* 2000 17-24-1959 170922 -1.22 / 98%
Watch the longest games LIVE.
* Slight regression is expected and normal at 100+1 time control. This will be our checkpoint.

Motto: Alone I can nothing, with God I can everything (St. Vincent Pallotti).

Conclusion: There is no strict proof, but there is a hope that CorChess is better on long time controls.