Stockfish 10 has just been released. While SF10 will surely top the computer chess rating charts in short order, there is a small problem with its implementation for those of us interested primarily in using it for chess analysis. There is a default contempt factor of 0.24 centipawns, meaning that SF10 will overestimate its position (from either side) by nearly a quarter of a pawn, regardless of the nature of the position on the board. This leads to increased results and Elo points against other engines, but it does distort the evaluations it produces.
It is easy enough to set the contempt=0 in an .ini file, but because I use SF10 in multiple programs, I compile my own version where the contempt is set to 0 by default. You can download my compile at:
There are four .exe files in the zip file. Which version should you use?
stockfish_10_C0_x64_bmi2.exe — for Haswell+ Intel processors
stockfish_10_C0_x64_modern.exe — for ‘modern’ AMD and Intel processors. Use this with Ryzen chips.
stockfish_10_C0_x64.exe — for generic 64 bit CPUs.
stockfish_10_C0_x32.exe — for 32 bit CPUs. (May not work. Let me know if it does for you!)
More information, including specific changes to source code, VirusTotal results, and why I haven’t shut off ‘dynamic contempt,’ can be found at my Stockfish for Analysis page, as well as in info.txt file included in the zip file.