Arbiters and illegal moves

[Kevin Thurlow]

Early in my chess career, my father explained that 0-0 and 0-0-0 were king moves and you could not move out of, into or through check. Soon after we had the situation that one of us played 0-0-0 when b1 (or b8) was attacked. As this did not affect the king it was ok. Many years later I had the great pleasure when an opponent played Rxb7 of responding 0-0-0+ followed by Kxb7. I managed not to laugh...

[Matt Mackenzie]

there was some old legend about korchnoi losing a game because he thought it was an illegal move to castle his rook through an attack and so got his king stuck in the centre because of it - someone else might be able to shed some light on that one?

This is the position. Korchnoi actually won the game, after checking with the arbiter that 0-0 was legal when the Rook was attacked.

Screenshot from 2022-07-27 20-31-46.png

And in this position, the win would have been quite a bit harder for Korchnoi without 0-0 as an option.

[AlanLlewellyn]

if you actually look at the position if he had spotted my illegal move and i had the play say kh2 then the game looked even anyway, i just thought his knight was in trouble and i could win it and completely overlooked i was in double check. But the ilegal move wins a piece so the rules need changing.

No, the rules do not need changing. What change would you propose?

if both players agree that an illegal move took place and they didnt realise at the end of the game i would propose both can agree within say a 24 hour period to notify the arbiter and ask that either they both agree that the game be declared void or that it be declared drawn depending on choice of the players.
that may seem a complex rule but the alternative is that as in my case i get a totally unwarranted point and rating points

[Roger Lancaster]

if you actually look at the position if he had spotted my illegal move and i had the play say kh2 then the game looked even anyway, i just thought his knight was in trouble and i could win it and completely overlooked i was in double check. But the ilegal move wins a piece so the rules need changing.

No, the rules do not need changing. What change would you propose?

if both players agree that an illegal move took place and they didnt realise at the end of the game i would propose both can agree within say a 24 hour period to notify the arbiter and ask that either they both agree that the game be declared void or that it be declared drawn depending on choice of the players.
that may seem a complex rule but the alternative is that as in my case i get a totally unwarranted point and rating points

Really? So after the last round of a weekend Swiss you could ask the arbiter to overturn a round 4 result? Please get real.

[IM Jack Rudd]

That sort of rule is probably workable for evening league chess. It wouldn't work so well in any sort of event where future pairings depend on past results.

[AlanLlewellyn]

would it be the end of the word if occasionally and it would be rarely it was found that a person on 4 points played someone on 4 but who got put back to 3.5, the void match would count .5-.5 in points terms in a swiss and final results are checked the day after the end of the tournament usually anyway so they would be declared re-adjusted scores

[Roger de Coverly]

as in my case i get a totally unwarranted point and rating points

Your opponent overlooked Queen takes King, not that an arbiter would actually allow you to play that. It's like missing a mate in one, if you don't spot it, your rating isn't justified.

[AlanLlewellyn]

as in my case i get a totally unwarranted point and rating points

Your opponent overlooked Queen takes King, not that an arbiter would actually allow you to play that. It's like missing a mate in one, if you don't spot it, your rating isn't justified.

i got carried away with the moment of trying to win the knight and thought i had, i planned Nxe2 in response to Ne2+ then realised it was illegal and thought maybe im in trouble here and he has a way to save his knight, and i didnt come to a conclusion when he played Ne2+ rather quickly and then i completely forgot about the double check and thought why dont i just play Nxe2, i have won his knight now so D'oh like a forgetful elephant(ie i am human) i thought i could get out of check that way and completely forgot about the double check till i tried to put the game in a computer for analysis.

[AlanLlewellyn]

after every otb standard rated game i play i analyse on an engine afterwards looking for mistakes in my game

[Joey Stewart]

You can agree whatever result you like with your opponent over the board regardless of the rules - I had a recent game in our summer rapid League where I was a couple of moves away from winning but moved my king into check (the checking piece was on my edge of the board right underneath me in a bind spot) and since our league didn't seem to have an official ruling regarding illegal moves in rapid games I offered a draw which seemed like a fair result for both of us given the situation.

I think, however, once an uncontested result has been submitted it really has to stand unless there are extenuating circumstances like the opponent has been found guilty of engine use and needs to be removed from a tournament.

[AlanLlewellyn]

are you insinuating something????

[Joey Stewart]

I actually forgot about your ICC problems when I wrote that, but I guess this is chess and old grudges die hard don't they. The main point I was making is that it is much less difficult to fix a result right after the game had finished and an irregularity has been discovered then it is to wait until days later, in the case of your game it was too late to really change anything since it sounds like it was just a genuine mistake that was visible to both players but both of you overlooked it on the day so it was fair enough to let the result stand.

It probably seems like a rare occurrence if you mainly play opens but if you have ever been to any schools chess events you would see it happen all the time and if there was a rule introduced where results could be redacted because an illegal move was discovered after the game then it would cause absolute chaos

[AlanLlewellyn]

I actually forgot about your ICC problems when I wrote that, but I guess this is chess and old grudges die hard don't they. The main point I was making is that it is much less difficult to fix a result right after the game had finished and an irregularity has been discovered then it is to wait until days later, in the case of your game it was too late to really change anything since it sounds like it was just a genuine mistake that was visible to both players but both of you overlooked it on the day so it was fair enough to let the result stand.

It probably seems like a rare occurrence if you mainly play opens but if you have ever been to any schools chess events you would see it happen all the time and if there was a rule introduced where results could be redacted because an illegal move was discovered after the game then it would cause absolute chaos

point taken but maybe make it a matter of choice for arbiter to implement

[Mike Gunn]

No, the rules about illegal moves are quite clear and work well (in my opinion). This is not an area where we need extra arbiter discretion. Once the game is over and the result is agreed by the players then that is it. Tournament chess is a sport and if you start altering game results afterwards you get chaos. Consider the parallel with football, VAR is bad enough as it stands but if you started changing decisions affecting the result of the game after it had finished ... what would it be like?

[Roger Lancaster]

You can agree whatever result you like with your opponent over the board regardless of the rules

No, I'm afraid not. If an event rules stipulate that draws by agreement aren't permitted within, say, the first 30 moves then you and your opponent would be unwise to try to agree one after 15 moves. There are probably other examples.