Getting and using a king

A man can step to at most two squares, both forward. A king moves along the diagonals in every direction, and in three of the four rule sets on this site it can fly any distance along them. How much that is worth is easy to measure: put a king on a square and read the engine's legal list.

One king, three counts

The black man on the top row is there only because a position needs two sides; it stands on none of those lines. The engine's default evaluation reflects the same gap. It counts a man as 100 points, a short king as 175 and a flying king as 300. Those are working values for its search, not laws of the game, but they show the size of what is at stake when a man nears the king row.

Getting one

A man is crowned on an empty square of the king row, so every man the opponent keeps at home closes one of those squares. Two men at home can hold up three attackers completely, as winning by blockade shows. The evaluation reflects this with a small bonus for each man still on its own back row while the other side has men left to crown.

When the door is shut, a forced capture can open it. In the Russian example in forcing captures, an offer drags the man off f8, and White's next move crowns on that very square.

Why a flying king changes every plan

Distance stops protecting anyone. The man on c3 is not even next to the king, and a short king on a1 could not touch it. A flying king takes it from where it stands and chooses where to land.

Safety becomes a question of lines. Against a short king you watch the squares beside it. Against a flying king you look along every open diagonal and ask what stands directly behind each man. A man on the edge of the board cannot be jumped at all, and two men next to each other on a diagonal cannot be jumped along it.

One line matters more than the rest. The long diagonal is the longest on the board, the evaluation gives a king a bonus for standing on it, and in endings it can decide how long the game may last, as draws and endgames explains.

The must-stop rule

Compare this with the one-man board above. With only c3 to take, the king had five places to stop. Add a man on f4 and the first stop is no longer free: a landing square ends the move only when no landing square of that jump can continue. From e5 the capture goes on over f4, so d4, f6, g7 and h8 are all refused. After the second jump the choice comes back, g3 or h2. The rule is the same in Brazilian, International and Russian draughts.

Use it both ways. When your king captures, work out the whole route first, because the rule may take away the landing square you had in mind. When you face a king, the rule tells you where it will have to stop, so you can have a man ready to jump it there.

A king has to capture too

Two men beat a flying king here, and compulsory capture is the whole reason. The king cannot decline the man on c5, and a3 leaves it just one landing square, right next to the man waiting there. So before you put a king on a fine diagonal, check what could be offered to it and where it would have to land.

Crowning is not the same everywhere

All four rule sets crown a man that ends its move on the king row. They part ways when it gets there in the middle of a capture.

• American checkers: it is crowned and the move ends, even with another jump in front of it. That jump has to wait for the next turn.
• Brazilian and International draughts: it stays a man unless the move ends on that row. With the most pieces rule choosing the route, a capture can carry your man straight past the crown.
• Russian draughts: it is crowned at once and goes on as a king in the same move, which is how the man on h6 takes three men in the Russian example of forcing captures.

When you aim a capture at the king row, ask where the move ends. Four rule sets compared plays out a matching position under each of the four. To practise getting a man through, try the Breakthrough to promotion theme on the puzzles screen.