A better next move

A square you control is not always a square you can keep. Read the top piece and the remaining space together.

This guide uses Standard: 4×4, a line of four, and stacks up to three pieces. Read the complete rules for variants.

1. Read the height before you take

A one-piece stack has two spaces left. A two-piece stack has only one. Taking the second type also locks it: the move changes ownership and makes that ownership permanent.

By contrast, taking a single O with X leaves a two-high stack. O cannot immediately retake it in Standard, but the square is still open after that restricted turn. You have gained control and a tempo opportunity, not a permanent square.

2. Self-stacking can help your opponent

You may add to your own open stack. But adding a second X above a first X leaves the final space available to O. That move can turn an open square into a locking opportunity for the other player.

Before fortifying, ask: can my opponent legally add the last piece next turn, and would that complete or block a line? Self-stacking is useful only when its timing and the rest of the board justify it.

3. Use the turn after a Take

Suppose O takes your one-high X by adding O. On your next turn, you must play somewhere else: Standard’s No Immediate Retake rule prevents taking that same square straight back. This restriction expires after your move elsewhere.

Use that forced move to make a threat, block an immediate loss, or claim another useful square. On O’s following turn, O may add the third piece to lock the taken square. Don’t plan as though a later retake is guaranteed.

4. Check immediate wins before long plans

In Standard, a complete line wins immediately; its squares do not all need to be locked. First check whether you can complete a line now. Then check whether your opponent can do so on their next turn.

Three top pieces in a row can be dangerous even if none is permanent. A beautiful future lock is no help if the opponent wins before you get another move.

5. Value squares by the lines they serve

On a 4×4 Standard board, every square belongs to a row and column. Squares on either main diagonal also contribute to that diagonal. A square serving several promising lines can give you more options, but stack height and immediate threats still matter more than a fixed opening recipe.

A useful practice routine

1. Play a Quick Play game against the computer.
2. Before each move, identify both players’ immediate line threats.
3. Count the remaining spaces on the square you want.
4. After the game, pick one move where control changed and consider a different destination.

Hints and Undo in Quick Play can help you explore. Streak omits those aids; use it when you want to test your decisions in consecutive games.

These are practical heuristics, not a solved opening book or a guarantee of winning.

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