Mancala

The board has two rows of six pits and a larger store at each end. The six pits on your side are yours, and so is the store to your right; the computer owns the other row and the store at the far end. Every pit starts with 4 seeds, so 48 are in play and each side begins with 24.

A turn is a single choice: pick one of your pits that has seeds in it. Lift all of them and sow them one at a time into the following pits, counter-clockwise — along your row towards your store, into your store, then along the opponent's row. You drop a seed in your own store as you pass it, but the opponent's store is skipped, so a big pit that runs all the way round never feeds your opponent's score.

Where the last seed lands decides what happens next. In your own store, you move again. In an empty pit on your side, you may capture. Anywhere else, the turn passes. There is no choosing how many seeds to sow and no choosing a direction: the pit you pick decides everything, which is why the game rewards counting before you touch anything.

Extra turns chain. A pit holding exactly as many seeds as it is steps from your store — one seed in the pit next to the store, two in the pit beside that, and so on — ends in the store, and if several of your pits are primed like that you can take them one after another. Play the one nearest your store first: sowing a pit further away drops a seed into the nearer one and spoils its count.

"Empty" means empty when the last seed arrives. A pit holding 13 seeds goes exactly once round the board — six of your pits, your store and six of your opponent's — and its last seed lands back in the pit it came from, which you have just emptied. The pit opposite has collected a seed on the way round, so a 13-seed pit always captures. With 14 or more, the pit you land in has already been sown into on the lap, so it is not empty and nothing is taken.

The moment all six pits on either side are empty, the game stops — it does not matter whose turn it would have been. Each player then banks every seed still sitting on their own side into their own store, and the stores are counted. More seeds wins; equal stores are a draw, 24 each in the standard game.

That sweep makes the ending a calculation of its own. Emptying your own side first hands your opponent everything left on theirs, so a player far behind in store can still win by running the other side dry while holding a full row. Once one store holds more than half of all the seeds — 25 of 48 — the result is settled, because a store never gives a seed back.

Yes. The six-pit, four-seed game has been solved by exhaustive computer search, and with perfect play from both sides the player who moves first wins. You move first here by default; the ⋯ menu hands the first move to the computer instead, which is the harder way to play.

Part of the reason is visible from the very first move. With four seeds a pit, your third pit from the left is exactly four steps from your store, so its last seed lands in the store and you go again before your opponent has moved at all. Each seed setting has one such pit: the fourth with three seeds, the second with five, the first with six.

Every level searches the actual rules — extra turns included, so a chain of store landings is seen as the run of moves it is. Easy's random pits and the tie-breaks between equally good moves are drawn from the game's own number, not the clock; only Hard's thinking time is real time, so a faster device lets it look further.

Hard searches one sowing deeper at a time — 1, 2, 3 and on — keeps a table of the positions it has already scored, and tries the best move from each round first in the next. Near the end of a game the whole remaining tree fits in its budget, and then it is not estimating at all: it plays the rest of the game out exactly.

The test suite plays Medium and Hard against Easy 24 times each, 12 games moving first and 12 moving second. Medium won all 24. Hard, held to 4,000 positions a move — a small fraction of what it gets through in its real third of a second — also won all 24, by an average of 23 seeds.

Mancala is not one game but a family of hundreds, played across Africa, the Middle East and Asia and known as sowing or count-and-capture games. The name comes from the Arabic root naqala, "to move". Oware in West Africa, Bao in East Africa, Omweso in Uganda and Congkak in Malaysia and Indonesia are all members, with their own boards and their own capture rules.

The six-pit, four-seed rules on this page are a young branch of that family. They were devised in the United States in 1940 by William Julius Champion Jr., and they are the version most Western boxed sets teach — which is why, for many people, they simply are "mancala". It shares a shelf with backgammon as a race decided by counting, but there is no die anywhere in it: every outcome is fixed the moment you choose a pit.