Stockfish 9

 

    I forgot to post that Stockfish 9 has just recently been released. The top five engines on the CCLR 40/40 rating list are:

1-Stockfish 9 64-bit 4CPU (3465)
2-Houdini 6 64-bit 4CPU (3441)
3-Komodo 11.2 64-bit 4CPU (3422)
4-Fire 6.1 64-bit 4CPU (3299)
5-Deep Shredder 13 64-bit 4CPU (3293)

     Several people have been pointing out that the default contempt setting has been changed from 0 to 20. One person thought it was because despite being the strongest engine, it missed the recent TCEC final because it drew many games due to the “0” contempt setting.
     I am not that familiar with all workings of engines, but one poster on one of the engine sites said that an engine can sometimes accept a draw because it has seen some lines which are slightly better for the opponent and as a result, it may start repeating moves in order to draw. To counteract this the contempt factor can be increased which tells the engine to play on. e.g. a setting of 50 means that the program will play for a win, even if it thinks its half a pawn down.  Download SF9