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by pengowray 609 days ago
> they show the time in seconds which can't be right

Seems right.

If you export/download games from lichess, they use the .pgn (Portable Game Notation) format, which is a standard plain-text format circa 1993, used by pretty much everyone for describing a chess game.

Lichess follows the specification to the letter, and as it only technically allows one-second accuracy, lichess only record moves with one-second accuracy. It seems insane, but that's how they do it.

Chess.com also exports PGN files, but they add a decimal place, allowing subsecond accuracy. No one has a problem with this. There is no software which cannot handle this. But Lichess refuses to "break" the spec.

lichess PGN export example:

> 1. d3 { [%eval -0.15] [%clk 0:01:00] } 1... g6 { [%eval 0.04] [%clk 0:01:00] }

Chess.com PGN export example:

> 1. d4 {[%clk 0:02:58.6]} 1... b6 {[%clk 0:02:59.2]}

1 comments

> lichess only record moves with one-second accuracy

According to this blog post, this doesn't appear to be the case since at least 2017:

https://lichess.org/@/lichess/blog/a-better-game-clock-histo...

"Move times are now stored and displayed with a precision of one tenth of a second. The precision even goes up to one hundredth of a second, for positions where the player had less than 10 seconds left on their clock."

Interesting. Thanks for the correction and link. I'll note though the .pgn downloads still only show 1 second precision, as do the game PGNs in lichess's "open database" archive.