Sometimes, because of events in other parts of the board, pawns are left on their own against the enemy King. When this happens, knowing one single rule will be enough to decide the game.
The Rule Of The Square
How can you tell if the enemy king can catch your pawn? One way is to calculate in your head, from the positions below:
"If I move my pawn to e6, then the king moves to c6, my pawn to e7, the king to d7, my pawn to e8 and I get a queen, but then the king takes my queen."
This works, as you see, but it's long and gives you too many chances to make a mistake. A second way is to count moves:
"Let's see, my pawn on e5 queens in 3 moves, while the king on b5 requires 3 moves to get to the queening square."Read more: The Pawns Alone