I think the upper bound is 6300, then. Each pawn can move 6 times, times 16 pawns, times 50 moves before a game ending draw, plus each capturable piece that ca

I think the upper bound is 6300, then. Each pawn can move 6 times, times 16 pawns, times 50 moves before a game ending draw, plus each capturable piece that can delay the game another 50 moves (15 on each side)