I've thought of a few different ways a chess game could go on moving only pawns, but I've only counted moves in one scenario:
- Both White and Black take 16 moves to line their pawns at the middle of the board.
- With a series of orderly captures in 8 moves, White and Black each wind up with 4 pawns each.
- Taking care to threaten the rooks first, White and Black move their pawns within striking distance of the opponent's non-pawn pieces. This would take 16 moves (bringing the total up to 40), except that...
- As soon as a White pawn threatens the Black king, Black would be forced to move the queen, a bishop or a knight to protect the king.
Have I thought through this scenario correctly? And even if I have, might could there be a scenario in which moving something other than a pawn could be put off longer?