White has a clear advantage, since white is up a pawn and having a more centralized king. White’s b-pawn is advanced, but not currently vulnerable to attack. White is playing to win. Black is hoping to draw. To draw, black must capture both of white’s pawns or reach a clearly drawn position.
Move 1 for White
White has six possible moves. d5 is the logical candidate move, but note that d5 relinquishes control over c5, allowing black’s king to attack the b-pawn. However, simple counting will show that it will take white five moves to queen his pawn versus eight moves for black. 1. d5 is the best move since it advances white’s plan in the most efficient manner possible.
Move 1 for Black
Black has four moves. We know that Kc5 does not work. The standard 1. … Kd7 gives white access to the c6 square. For example, 2. Ke5 Ke7 3. d6 Kd7 3. Kd5 Kd8 4. Kc6. Therefore, black plays 1. … Ke7, which turns out to be the move that most interferes with white’s strategic objectives.
The game continues 2. Ke5 Kd7 3. d6 Kd8.
Move 4 for White
Now 4. Ke6 Ke8 5. d7 Kd8 6. Ke5! leads to the same position as 4. d7, so 4. d7 is the most efficient move.
Move 4 for Black
4. … Ke7!? 5. d8Q+ Kxd8 6. Kd6 makes things easier for white than 4. … Kxd7 5. Kd5. White now has the offensive opposition and can win the b6 pawn and the game.