b ) Pawn on the sixth rank
When the pawn is on the sixth rank, prospects for Black to draw are much stronger. Especially if its king is in front of the pawn, with an active rook. Passive defence with the rook on the eighth rank does not bring success in positions with the pawn on the central or “bishop” file. Black to move loses. Due to the mating threat, his rook is connected to the eighth rank, which can be used by White to attack and win from the other side.