Five in a Row
Take turns placing black and white stones; the first to line up five in a row, column or diagonal wins. Play the computer and find out why a three or four with open ends is so strong.
Tap a point to place your stone.
You are Black (first). Move 0
How to play
Tap an intersection to place a stone. Black moves first and you alternate; the first to get five or more in a row, column or diagonal wins. Six or more (an "overline") also wins, and there are no forbidden moves, so these are the basic rules. The board can be 11×11 up to 15×15 (it starts at 11×11 on phones). "Hint" shows the best point by the current evaluation with the reason, and "Auto-play" lets the computer play both sides until the result.
Learn more
Going first is an advantage in this game. The shapes that matter are a three with one open end, a three with both ends open (an "open three"), and a four. A four with both ends open cannot be stopped from both sides at once, so making one is as good as winning. At "Strong", the computer first checks for "make five", "block five" and "make an open four". If none applies, it counts every group of five squares on the board and searches ahead, within its time budget, for the point that builds its own lines and spoils yours. The evaluation is approximate, so it can miss things. "Normal" looks two moves ahead; "Easy" picks among a few promising points.