Hi,
Can we make a api request for post tournament results and have a column that shows each players rating at the start of the tournament vs the end of the tournament? because if they start at 1700 and at the end of the tournament jump to 1850 and there is a U1800 prize or trophy they wont be eligible with the current api because I believe it only shows the post tournament rating. In most fide and uscf tournaments a players pre tournament rating is used to decide their ability to compete for class trophies and prizes.
Which pre-tournament rating? Do you mean the rating at the time the player joined the event, the time the event started, the time the player started their first game, or the time the player most recently joined (if they were kicked out and rejoined)?
the rating at the time the tournament started. Good differentiation you point out.
What if the player's rating changes at the same second the tournament starts? Would a tournament with hundreds of players have its start delayed to check whether any games are in progress?
It should just be the rating from the first game they complete in the tournament marked as pre tournament rating vs post tournament rating. Good outlier edge case. your a programmer I'm guessing.
Yeah, there's lots of use cases like that to consider, especially given a NoSQL (non-relational) database where these sorts of lookups don't perform well or aren't easy to implement & tend not to be implemented/supported...
Is there a way to know how the elo is calculate based on the performance rating of a tournament. Example you enter the tournament at 1400 and performance rating is 1800 therefore your post tournament rating is xyz. Then we can get a very close number to pre tournament rating if there is some sort of mathematical relationship between those two numbers or we know how the elo is adjusted after each game.
Excellent question; unfortunately, there is none that I know of.
I'm taking a closer look at the API and it might be painful, but sufficient to parse every PGN for WhiteElo and BlackElo:
lichess.org/api#operation/gamesByTournamentmaybe you guys can add an api call that allows us to know the exact rating of each player at an specific time stamp but if your using NoSQL i'm not sure if you have that data saved? but since the pgns are saved in the game history each of those games have a time stamp and rating stamp associated with the pgn so that should be easy?
