Checkers Shots: How to Set Up a Two-for-One (and Dodge One)

A shot in checkers is a move that gives away a piece on purpose: your opponent has to jump it, because jumps are compulsory, and that jump lands their man where you can jump two or more back. The classic is the two-for-one. In 5,000 games between Poozee's Medium computer players, 10.7% of games had a shot that won material, and the side that landed the first one won 68.0% of those games and lost only 9.9%.

Below is what counts as a shot, how to set up a double jump step by step, the shapes that came up again and again, and the check that keeps you from walking into one. Every diagram is a real position, checked with the engine behind Poozee's Checkers. If you need the rules first, start with how to play checkers.

What counts as a shot

Checkers players have used the word for a long time: P. H. Ketchum's 1923 manual, Checkers: The Handy Manual, describes some openings as full of traps and shots. To count them, we needed an exact rule. We counted a move as a shot when:

1. it jumps nothing,
2. it leaves the opponent a compulsory jump, and
3. once nobody has a jump left, the player who made it has taken more pieces than it lost, with both sides picking their jumps as well as they can.

A king counts as one piece. Squares are named from Red's side: columns a to h from the left, rows 1 to 8 from the bottom. Black moves down the board and Red moves up.

How we tested. Two copies of the Medium computer played 5,000 seeded games from the start. Medium looks 4 plies ahead (two moves by each side), follows every jump to the end, and picks at random among its best moves, so the games differ and each one replays exactly. To check a stronger player, we also had the Hard computer, held to 8 plies, play 490 games: 10 from each of the 49 two-move openings, because at a fixed depth Hard plays nearly the same game from one position. A computer that sees a few moves ahead isn't a master, so read the numbers as what happens between two players who look a couple of moves ahead.

How to set up a two-for-one, step by step

Most of the opening shots we found (more on them below) end like this one. Black has moved its man off h6, and Red sets up a double jump that ends on that empty square.

Black's only legal move is to jump from c5 over d4 to e3. That puts a black man on e3, right in front of Red's man on d2, with f4 empty behind it. So Red's d2 man jumps twice in a straight line: over e3 to f4, then over g5 to h6.

To build one yourself, work backward from the second capture:

1. Find an enemy piece with an empty square behind it, seen from your side. That's your second capture, and the empty square is where your double jump ends. Here it was g5, with h6 empty.
2. Find the square that lines up the first capture: an enemy man there would sit diagonally in front of one of your men, with an empty square beyond it that leads to the second capture. Here it was e3, in front of d2.
3. Give a man so the forced jump lands on that square. Red's e3-d4 left Black no choice but to jump from c5 to e3.
4. Check every jump your opponent can make. If they have more than one, they will pick the one that hurts you least, so the shot has to work against all of them.
5. Count to the end. Follow the jumps until nobody can jump, and make sure you come out ahead.

The 18 opening shots

Our checkers openings guide found 54 second moves for Black that lose a man, 18 of them to a shot. By the rule above, 16 of those 18 are shots, and 15 are a two-for-one ending on h6, each after Black played h6-g5: 7 run straight from d2 like the one above, and 8 turn a corner from h2 (over g3 to f4, then over g5 to h6). The 16th, after b6-a5, c3-d4 and a7-b6, is Red's d4-e5, which gives two men and takes three. In the other 2, the jumps come out even, but Black loses a man a few moves later anyway.

Pro tip: As Black, h6-g5 leaves h6 empty, and a red double jump can end there. Before you play it, look at Red's men on d2 and h2 and ask whether a forced jump could drop one of your men onto e3 or g3.

The shapes that come up most

Across the 5,000 Medium games there were 551 shots that left the shooter ahead (more on why that's fewer than you'd think below). Here's how the shooter took its pieces back:

By pieces, 449 were give one, take two (81.5%), 75 were give one, take three (13.6%) and 23 were give two, take three (4.2%). The corner is the shape to look for most: a man jumps one way, then turns 90 degrees to take a second piece.

Black must jump from h4 over g3 to f2. Then Red's man on g1 jumps over f2 to e3 and turns the corner, over f4 to g5. Red started the fight four pieces against four and finished it three against two.

Kings shoot backward. In 194 of the 551 shots (35.2%), a king made at least one jump down the board, which a man can't do. That makes kings dangerous in a crowded middle game:

Red's jump from f6 over g7 to h8 is forced, and it even crowns a king. But it empties f6, and Black's king on d4 jumps three: over e5 to f6, over g5 to h4 and over g3 to f2. Black goes from six pieces against five to five against two.

A two-for-one isn't always a win

Here's the surprise in the data. In the 5,000 games, a player made a move that won the jumps after it 2,081 times, but only 551 of those left the shooter ahead of where it stood before the fight began. A fight here means a run of exchanges with no quiet move in between: give a man, get jumped, give another, jump back.

• 1,458 ended the fight even. In 1,338 of them, the shooter had started the fight itself by giving a man away and only won it back. Giving a man and then winning it back with a shot is a common way to trade.
• 72 left the shooter behind: it was answering a fight that had gone against it, and only cut its losses.

So when you spot a two-for-one, count from the start of the fight, not from the shot. And when your opponent hands you a man, look past the jump you're forced to make: it may be the first half of a trade like that one, or of a real shot.

When shots happen, and what one is worth

Shots that won material came mostly in the early middle game. Counting each player's move as one move (so move 23 is each side's 23rd), the median shot came on move 23, and half of them came between moves 16 and 31:

A shot's extra piece usually sticks: after 6 more plies of best play, the shooter was still at least a piece up in 524 of the 551 (95.1%). Of the 534 games with a winning shot, the side that landed the first one won 363 (68.0%), drew 118 (22.1%) and lost 53 (9.9%). A man up is a big edge, not a guaranteed win.

The Hard computer didn't make shots go away. Its 490 games had a winning shot in 90 (18.4%), more often than Medium's games. But a shot settled less: the side that landed the first one won 49 of those 90 games and drew 35. The two studies started from different positions, so compare them loosely.

How to avoid walking into a shot

Most shots are avoidable, and the clue is usually the move you just made. We looked at the 402 winning shots that started a fight, where the move before the shot wasn't a jump:

• In 399 of the 402, the victim had at least one other move after which there was no shot at all.
• In 242 (60.2%), the piece the victim had just moved was part of the shot: the shooter jumped it in 175, and in 67 it was the man forced to jump.
• In 115 (28.6%), one of the jumps landed on the square the victim's move had just left.

That gives a three-question check before every move:

1. The piece you're moving: after it lands, could your opponent give a man that forces one of your pieces to jump, and then jump the piece you just moved?
2. The square you're leaving: could an enemy jump end there? A back-row man that steps forward, like h6-g5, opens exactly that kind of hole.
3. Every forced jump: if your opponent can make you jump, where does your man land, and what can jump it then?

The same questions find shots for you: ask them about your opponent's last move. Our checkers strategy guide has another two-for-one to practice on, along with the habits that won the most games in our tests. On Poozee, Easy misses a lot, so it's a good place to try your first shots, and the Hint button shows the move the Hard computer would play.

Keep playing

• Play Checkers against the computer or a friend
• Checkers opening moves for beginners: all seven first moves, and the early mistakes that give away a man
• How to win at checkers: back-row defense, trades and two kings against one
• How to play checkers, with forced jumps, kings and draws