CorChess is a clone of Stockfish [source code] [source with Large Pages support] maintained for better performance on long time controls,
trying at least partially to fill the gap between regular tests and demands of correspondence players.

My main idea is to improve the following scalability of Stockfish 8.
From February 15, 2018 all patches are tested at 160+1.6 time control (1 thread, 64 MB hash, until clear decision).

Please contact me ( about your experiences with CorChess,
or in the case that you want to be on the CorChess mailing list.

I mainly use strong 2moves book.

Regression tests and tournaments between CorChess and Stockfish
Version Opening book Time control #games Result Elo gain
CorChess 1.3 2moves_v1 160+1.6 10000 / 10000 1236-1182-7582 +1.88
CorChess 1.5 8moves_v3 2500+25 512 / 512 26-22-464 -
CorChess 2.4 2moves_strong 160+1.6 4000 / 4000 367-399-3234 -2.78
Regression tests will be done after several patches. Watch games LIVE.

From Stockfish to CorChess (in detail)

If you want to support the project please send your small donations by PayPal to
The amount of donated money will be displayed here (within 48 hours), and it will be used only for testing CorChess.
You can also send your ideas / codes on how to improve Stockfish on higher depths (above 20).

Money donated so far: $70, 50

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