The board and the goal

Quitapon pits Blue against Red on a board with eight columns and eight rows. Blue starts. Each player controls only tiles of their own color, although both have the same numbers available. A blue 4 and a red 4 belong to different players and can never work together in a winning line.

In this book, columns run from A to H from left to right and rows from 1 to 8 from top to bottom. A1 is the upper left corner; H8 is the lower right. A1, B1, C1 and D1 form a horizontal row. A1, A2, A3 and A4 form a vertical column. The number printed on a tile is separate from its row number.

Each player starts with 32 tiles: four copies of every number from 1 to 8. You choose which number to place, provided a copy remains in your reserve. Tiles are not drawn randomly. Placing a 5 spends one copy of 5; if that tile is later removed, you recover that exact copy.

The two colors have independent reserves. Red having four 3s on the board does not prevent Blue from using their own 3s. However, if all four of your copies of 3 are already placed, you cannot place a fifth. Get into the habit of checking your reserve before imagining a combination.

A valid line occupies four consecutive cells in a single direction and contains only your color. The numbers must either match, such as 6–6–6–6, or change by one at each step in order, such as 2–3–4–5. Descending order also works, such as 7–6–5–4. Horizontal, vertical and both diagonal directions are allowed.

Collecting the right numbers in any order is not enough. A row containing 2–4–3–5 is not a straight. An empty cell between tiles breaks continuity, and an opposing tile breaks the color requirement. Before considering strategy, check these three conditions separately: position, color and numbers.

Completing four creates a provisional line. You have not won yet: your opponent starts their next turn by removing one of your tiles. You win only if some valid line of your color still exists after that removal. This rule puts defense and simultaneous threats at the center of the game.

Imagine four blue 6s at A1, B1, C1 and D1, with no other blue line. Red can remove B1 and break the combination. If Blue also had a valid line on A8–D8, removing B1 would leave that other line intact. You do not need to preserve the original particular line; you need to preserve at least one line.

Start by identifying whose turn it is and which action comes next. Then locate the opponent’s completed lines, your nearby opportunities and your available tiles. In exercises, read the goal before touching the board: completing a line, defending and creating a resilient position are different tasks, even though they share the same rules.

When you make a mistake, find the exact condition you missed. Perhaps you mixed colors, misread a diagonal or confused a provisional line with a win. Correcting that detail helps more than memorizing a cell. The following chapters add one idea at a time so that you can explain your decisions as well as choose correctly.