This page is about POLY 1.6, a continuation on the 5 first versions. After intensive testing we concluded that from all the options available from version 1.2 and 1.5 the WLD (win|loss|draw) approach gives the best results. With version 1.6 we like to present a number of (reasonable well) tuned polyglot opening books included in the download.
For this purpose (from MillionBase 3.45) we created 5 regular polyglot books based on a minimum human elo of: elo2500, elo2600, elo2650, elo2700, elo2750 and 1 polyglot book from CCRL 40/15 games played by engines with a minimum elo of 3300. Six matches of each 5000 games with the new Stockfish 12 should give us insight which book scores best. For reference we use the last handcrafted ProDeo book from Jeroen Noomen.