Also, the reason it is 50 moves <em>without a pawn move or capture</em> is because both pawn moves and captures are irreversible. In fact, the only irreversibl

Also, the reason it is 50 moves <em>without a pawn move or capture</em> is because both pawn moves and captures are irreversible. In fact, the only irreversible move that doesn't reset the 50 move rule is castling (or losing the right to castle), as having the ability to castle technically changes the position.