Strategy › Endgame

The checkers endgame: kings, the move and the double corner

Winning a piece is only half the job. With a few pieces left, checkers becomes a game of precise counting, where one tempo can decide the result. These are the endgame ideas every player needs.

What wins and what draws

A few basic results are worth knowing by heart:

• One king against one king is a draw. Neither king can trap the other on an open board.
• Two kings against one king is a win, even if the lone king reaches a double corner. The technique is shown below.
• An extra piece usually wins, but only if you can turn it into kings and avoid being blocked. A piece that can't move is worth nothing at all.

That is why the side that is ahead should trade pieces: each even exchange brings the position closer to one of these known wins. The side that is behind should avoid trades and look for a draw.

The double corners

The pairs of squares in two corners of the board, 1 and 5 on Red's side and 28 and 32 on White's, are called the double corners. A lone king sitting in one can step back and forth between its two squares, and it can only be captured if it is driven out. Against a single enemy king that is enough to hold a draw for ever. Against two kings it isn't, but it's still the best defense, because it makes the attacker find the right technique.

Two kings against one

Red's plan has three steps, and the engine confirms it wins against any defense:

1. Bring one king next to the corner. Red plays the king from 22 round to 27 (22-26, 26-31, 31-27) while White shuttles between 28 and 32. The second king waits on 18.
2. Take away the second corner square. With White's king on 32, 18-23 leaves it a single move, back to 28. Then 27-32 occupies the corner square White just left. White's king on 28 is now surrounded on two sides and must step out with 28-24.
3. Hunt it down. Out of its corner, the lone king runs along the edge of the board. Red follows with one king, 32-28, and blocks the escape with the other, 23-18, 18-15, 15-11, until every square the White king can reach is next to a Red king. When it steps to 24, the king on 28 captures it.

The whole sequence takes ten Red moves against the most stubborn defense. Follow the link under the diagram and try it yourself against the computer, which will defend as well as it can. The key moment is step 2. If you rush to attack before your kings control the squares around the corner, the White king simply keeps shuttling.

The move

In checkers you can't pass. When the pieces are close together, the player who has to move may have only bad moves left. Having the move, also called the opposition, means arranging things so that your opponent is the one who runs out of safe moves first.

The simplest possible example is one piece each, heading toward each other:

Each side has a single piece, and Red's can't get past White's. With Red to move, the pieces walk toward each other, 3-8 27-24 8-12 24-20, until Red has to step next to White's piece, 12-16, and is captured, 20x11. Whatever route Red takes, the result is the same.

Change nothing but whose turn it is, and the result reverses: 27-24 3-8 24-20 8-12 20-16 12x19. Nothing about the pieces changed. Only the count of moves did.

With more pieces, the same idea decides whether a blocked position is won or lost, and strong players count spare moves (tempo) well before the endgame arrives. A practical rule: in a blocked position, before you commit, count how many safe moves each side has left. If you will run out first, you need to change the structure, usually with an exchange, while you still can.

Converting an advantage

1. Crown your pieces. Kings win endgames. An extra ordinary piece blocked on the side is not an extra piece at all.
2. Trade when ahead. Offer exchanges that leave you with the same lead and fewer pieces on the board.
3. Watch the double corners. Don't let a lone enemy king settle into one if you can stop it, and know the technique above if it does.
4. Keep checking for shots. The side that is behind has nothing to lose, and a single two-for-one can turn a win into a draw.

Practice

Play the two-kings position above until you can win it every time. Then play full games against the computer on Hard or Expert. Both search deeper as pieces come off the board, so they defend endgames well, and will punish a careless king. For sharper tactical practice, try the puzzles.