MillionBase 3.45 - 3.45 million (human) quality chess games in PGN and SCID format. The 2 yearly TWIC update, added 550.000 new games from the years 2018, 2019 and 2020. Database up to date till October 6, 2020.
Chris Whittington contributed 41 million EPD positions analysed by Stockfish 11 at 25ms for Texel Tuning. In his own words:
Files contain 41 million EPD’s, sampled from LiChess PGN Database of human games on rebel13.nl
All with evaluation by Stockfish 11, search set at 25 milliseconds. Format is 6-part FEN plus centipawn evaluation, POV side on move. Filtered for a) legality, b) availability of more than one legal move from the position and c) not immediately game terminal. Sampling rate from PGNs was around 12%
rnb1k2r/ppppqppp/5n2/4N3/1bPP4/2N5/PP2PPPP/R1BQKB1R b KQkq - 0 1; sf11=-89.0
r1bqk2r/pp1pppbp/2n3p1/8/2P1N3/1P3N2/P2QPPPP/R1B1KB1R b KQkq - 0 1; sf11=170.0
1r1q2kr/p6p/1nB2p1B/3b1P2/3p2P1/5Q1P/PP6/R4RK1 w - - 0 1; sf11=381.0
8/k7/P5R1/1Pb5/2P2r2/3K4/8/8 b - - 0 1; sf11=0.0
rn3k1b/4p2p/bqp2np1/p3P3/1p6/3B1P2/PPPQNNP1/R3K2R b KQ - 0 1; sf11=-678.0
2r1n1k1/1p3p1p/3p2p1/1p1Pp3/1B2P3/1P2bP2/P3N1PP/1R5K w - - 0 1; sf11=-20.0
8/4kp2/7p/5K1P/BP4P1/b7/8/8 b - - 0 1; sf11=-13.0
Suitable, and designed for (Texel) tuning of chess evaluation function. These are suitable for first shot tuning, proof of concept. Chess engine programmers would probably want to later develop their own testing sets and their own evaluations.
Release is into Public Domain. Thanks to Ed Schroeder for hosting.