Recently a game was played where two GMs swapped kingside and queenside knights and then agreed a draw (and got their just dessert): How often can the starting position be repeated in a game without automatic draw? Since even four castling rights can be forfeited, the answer surely is "75 moves".

Thus my not 100% FIDE-compliant, but mathematical more interesting question is that you assume automatic draw on fivefold repetition but NOT on 75 moves without pawn move or capture, and no player claims. This will be a very large number, in the order of (32 over 4).

Recently a game was played where two GMs swapped kingside and queenside knights and then agreed a draw (and got their just dessert): How often can the starting position be repeated in a game without automatic draw? Since even four castling rights can be forfeited, the answer surely is "75 moves".

EDITED OUT: The not 100% FIDE-compliant, but mathematical more interesting question is that you assume automatic draw on repetition but NOT on 75 moves without pawn move or capture, and no player claims. This will be a very large number, in the order of (32 over 4).

Since recently a game was played where two GMs swapped kingside and queenside knights and then drawed (and got their just dessert): How often can the starting position repeated in a game without automatic draw? Since even four castling rights can be forfeited, the answer surely is "75 moves". Thus my not 100% FIDE-compliant, but mathematical more interesting question is that you assume automatic draw on fivefold repetition but NOT on 75 moves without pawn move or capture, and no player claims. This will be a very large number, in the order of (32 over 4).

Recently a game was played where two GMs swapped kingside and queenside knights and then agreed a draw (and got their just dessert): How often can the starting position be repeated in a game without automatic draw? Since even four castling rights can be forfeited, the answer surely is "75 moves". 

Thus my not 100% FIDE-compliant, but mathematical more interesting question is that you assume automatic draw on fivefold repetition but NOT on 75 moves without pawn move or capture, and no player claims. This will be a very large number, in the order of (32 over 4).