Ggtkuk

May I know how to find in all grandmaster games, what the percentage of each of the following is?

• Kingside castling


• Queenside castling


• Never castled by the end of the game but still has the right to castle


• Lost the right to castle

Note When one side has castled more than once in a game, only the first castle counts.

If you are prepared to use standard Linux command-line tools like wc and grep then I think my free PGN processor, pgn-extract, will do much of the pre-processing necessary to count games in each category. Below is a basic bash script I put together as a proof of concept. It assumes your file of games is called inputfile.pgn - adjust as necessary, or pass it in as a command-line argument:

#!/bin/bash

# Output stats on castling.

src=inputfile.pgn

# Pre-process the games to allow textual analysis.

pgn-extract -C -V -N --notags --nochecks --linelength 10000 -s -o stripped.pgn ${src}

# Castling by white: detect a preceding move number.

grep '. O-O ' stripped.pgn > Wkingside.pgn

grep '. O-O-O ' stripped.pgn > Wqueenside.pgn

# Castling by black: detect no preceding move number.

grep '[^.] O-O ' stripped.pgn > Bkingside.pgn

grep '[^.] O-O-O ' stripped.pgn > Bqueenside.pgn

# Find games in which no castling occurred.

grep -v ' O-O ' stripped.pgn | grep -v ' O-O-O ' | grep -v '^$' > nocastle.pgn



# Output the FEN of the final position to include castling rights and

# look for the presence of rights.

pgn-extract -C -V -N --notags --nomovenumbers --linelength 10000 -s nocastle.pgn --dropply -1 -F | grep ' [wb] [KkQq]' > rights.txt



# Output the results - assumes valid Result tags in the source.

echo 'Number of games: ' `grep '^[Result ' ${src} | wc -l`

echo 'W Kingside: ' `cat Wkingside.pgn | wc -l`

echo 'W Queenside: ' `cat Wqueenside.pgn | wc -l`

echo 'B Kingside: ' `cat Bkingside.pgn | wc -l`

echo 'B Queenside: ' `cat Bqueenside.pgn | wc -l`

echo 'Neither: ' `cat nocastle.pgn | wc -l`

echo 'Rights retained: ' `cat rights.txt | wc -l`

I tried the script on the KingBase database (Apr 2019) and, after removing broken games and duplicates got the following stats:

Number of games:  2072354

W Kingside:  1633762

W Queenside:  246158

B Kingside:  1670870

B Queenside:  128124

Neither:  69776

Rights retained:  24280

The 'neither' figure is about 3.4% while the 'rights retained' figure is about 1.2%. If games with 20 or fewer ply are removed then the 'neither' figure reduces to about 2.9% and the 'rights retained' figure to about 0.7%.

Just googling for "castling statistics" already yields a few results; even though the analysis is done on a different set of games than 'all grandmaster games', it gives a rough indication.

• 50 world class players


• 2 million games in the MillionBase database

Kingside castling is done by 80-81% of the players, and queen side castling by 8-9%. I estimate that Never castled by the end of the game but still has the right to castle is negligible (less than 0.1%, since it requires a very short game). So that leaves about 11% for the final group Lost the right to castle.