Track the evaluations of the book exits from chops.pgn
on chessdb.cn (cdb). The name of the book
stands for Complex Human OPeningS.
The book is based on the book created by Joost VandeVondele in October 2024, that was originally
named
book_caissa_minElo2500_maxPlies24_cdb-082-102_softmax_d4_a10_4d_0.99_1.5d.pgn
when it was announced on discord. The original book contained a total of
7320 lines from games in Caissabase that were
played between 2500+ Elo human players and that lead to positions that
current engines judge to be on the edge between a win and a draw. In addition,
the positions were chosen so that for the next two full moves
both sides have a variety of playable options,
meaning that (engine) games starting from these positions are likely to
diverge quickly.
The lines in chops.pgn are a subset from the lines in the original book that
lead to the same 3588 unique positions (without move counters), with shorter
lines being preferred where possible.
The lines are between 2 and 24 plies long, with an average of
16.8 plies. The 3588 unique book exits are stored in chops.epd.
This repo tracks the evaluations of the positions in chops.epd on cdb.
On cdb they have an average depth of 16.6 plies, as well as 30.6 pieces on
average. No position has fewer than 22 pieces on the board.
The file chops_cdbpv.epd
contains the current cdb evaluations and PVs for each position. It is created
daily with the help of the script cdbbulkpv.py from
cdblib, and the obtained statistics
are written to chopstrack.csv.
Moreover, each day the hundred positions with the currently shortest PVs on cdb
(ignoring PVs ending in a two-fold repetition)
are written to chops_daily_shortest.epd, and
the positions with absolute evaluations in the interval [90, 105]
are written to chops_daily_edgy.epd.
The following graphs attempt to measure the progress cdb makes in exploring
and evaluating the positions in chops.epd. See
caissatrack
for a precise description of the plotted indicators.
To discuss anything cdb related, and to help cdb grow at a healthy pace, join other (computer) chess enthusiasts at the chessdbcn channel on the Stockfish discord server.