Is it possible to have 18 queens on the board in a legal game of chess?

[glee]

@glee

Decades ago I saw a last-round game in the British Championship where the position was repeated six times before they agreed a draw.
Both players needed a win to get a lot more prize money (and probably a shot at the title.)

And here is that game - very entertaining!

Ward vs Hodgson (1993) BCF-ch

[AppallingGael]

@TimeWinder

Like anyone’s going to argue with that username :- )

I will. Threefold occurrence, twofold repetition.

[Malacandra]

I appreciate the logic of your position, but the phrase that’s used is “threefold repetition” and you need to get the authorities to change their tune before you win internet arguments on the strength of your point.

[Chronos]

It was my understanding that threefold repetition required a claim, but that 50 uneventful moves did not.

Also, studies of tablebases have revealed that there exist situations where one side could force a checkmate, but requiring more than 50 uneventful moves, which have prompted some to call for a change to that rule.

[borschevsky]

For that reason it was changed to a 100-move rule for a while, but it’s since been changed back.

[TonySinclair]

@Chronos

It was my understanding that threefold repetition required a claim, but that 50 uneventful moves did not.

Also, studies of tablebases have revealed that there exist situations where one side could force a checkmate, but requiring more than 50 uneventful moves, which have prompted some to call for a change to that rule.

Has anyone determined the maximum number of moves ahead a human can see in a winnable game? Even for a grandmaster and with just a few pieces on the board, 50 seems awfully high. I’m not saying it should make any difference in the rule, but I’m curious.