A game is solved when its result with perfect play is known. Tic-tac-toe, checkers and Quarto are draws. Connect Four is a win for the first player. Chess and Go are not solved. The table below lists the best-known solved games with their results, who solved them and when, from Wikipedia's list of solved games, read on October 28, 2026.
About us: we make Quads, a game built on the same mechanic as Quarto and not affiliated with its publisher. We've run our own solver on Quarto endgames, and that's why we keep this list. Results are as Wikipedia reports them. Where that article flags a claim as needing a citation, we left it out.
Three levels of "solved"
Game theorists separate three strengths of solution. These definitions follow the Wikipedia article:
| Level | What is known | Example |
|---|---|---|
| Ultra-weak | Who wins (or that it's a draw) from the starting position, with perfect play, without necessarily knowing how. | Hex: the first player wins, proven without a strategy for full-size boards. |
| Weak | A strategy that achieves the perfect-play result from the start, against any opponent. | Checkers (2007). |
| Strong | The best move from every legal position, including ones reached after mistakes. | Connect Four, tic-tac-toe. |
The list
| Game | Result with perfect play | Solution | Solved by | Year |
|---|---|---|---|---|
| Tic-tac-toe | Draw | Strong | Trivially solvable | – |
| Wythoff's game | Known for every position | Strong | W. A. Wythoff | 1907 |
| Qubic (4×4×4 tic-tac-toe) | First player wins | Weak | Oren Patashnik; Victor Allis | 1980 |
| Ghost (word game) | Solved | – | Alan Frank | 1987 |
| Connect Four | First player wins | Strong | James D. Allen; Victor Allis (independently) | 1988 |
| Nine men's morris | Draw | – | Ralph Gasser | 1993 |
| Gomoku (free-style) | First player wins | – | Victor Allis | 1993 |
| Quarto | Draw | – | Luc Goossens | 1998 |
| Teeko | First-player win or draw, by variant | – | Guy Steele | 1998 |
| Pangki | Draw | Strong | Jason Doucette | 2001 |
| Awari (Oware) | Draw | Strong | Henri Bal and John Romein | 2002 |
| Checkers (English draughts, 8×8) | Draw | Weak | Jonathan Schaeffer's team | 2007 |
| Fanorona | Draw | Weak | Maarten Schadd | 2008 |
| Three Musketeers | The blue side wins | Strong | Johannes Laire | 2009 |
| Morabaraba | First player wins | Strong | Gábor E. Gévay | 2015 |
| Losing chess | White wins (with 1. e3) | Weak | Mark Watkins | 2016 |
| Othello (8×8) | Draw (contested) | Weak | Hiroki Takizawa | 2023 |
Notes: "–" means the source doesn't state that field. Connect Four was solved by James D. Allen on October 1, 1988 and independently by Victor Allis on October 16. Its strong solution came later, through a 1995 database by John Tromp and a 2025 table for the full 7×6 board. The Othello result is weak and its conclusions are contested. The full list, including variants and smaller games such as Hexapawn, Kalah and Pentago, is on Wikipedia.
Games on this list by the decade they were solved
Partly solved and unsolved games
- Chess: not solved. Every position with up to 7 pieces on the board has been solved, through endgame tablebases.
- Go: not solved at full size. The 5×5 board was weakly solved in 2002, and 7×7 results have been reported since.
- Hex: the first player wins on every board size, a classic strategy-stealing proof. But explicit winning strategies are known only for small boards, up to 9×9 by the article's account.
- International draughts (10×10): not solved. Some endgames are, and computer analysis suggests a draw is likely.
Quarto, solved and solved again
Quarto is the 4×4 game in which your opponent chooses the piece you place. It was solved by Luc Goossens in 1998: with perfect play neither player can force a win, so it's a draw. Wikipedia adds that the result was corroborated again in 2026. Researchers have kept working on it, including a 2023 report from UC Berkeley on solving and visualising large games and a 2025 TU Graz thesis, Ultra-strongly Solving the Board Game Quarto, by Christian Rahstorfer.
The solved result covers the classic rules, with rows, columns and diagonals. Many editions also let a 2×2 square win. We haven't solved that variant from the empty board, but we did solve over 13,000 random endgames exactly under both rule sets. With squares, draws all but disappear in the late game. The numbers are in Is Quarto solved?.
Does solved mean easy?
No. A solution is a fact about perfect play, usually found by a computer searching billions of positions. It doesn't make the game easier for people.
- Checkers needed years of computer search to settle, and strong human players still lose games.
- Connect Four is a first-player win, but the winning line needs exact play from move one. Most players don't know it.
- Quarto is a draw, but one careless hand-off loses on the spot. In our tests, even strong computer players squeezed each other into losses in most games.
For a side-by-side look at three of these games, see Quarto vs Connect Four vs tic-tac-toe.
Frequently asked questions
What does it mean for a game to be solved?
That the result with perfect play from both sides is known. A weak solution gives a strategy that achieves it from the start; a strong solution gives the best move from every position.
Is chess solved?
No. Positions with up to seven pieces are solved through endgame tablebases, but the full game is not.
Is Connect Four solved?
Yes. It was solved in 1988, independently by James D. Allen and Victor Allis: the first player wins with perfect play.
Is checkers solved?
Yes. Jonathan Schaeffer's team weakly solved English draughts in 2007: it is a draw with perfect play.
Is Quarto solved?
Yes. Luc Goossens solved Quarto in 1998: it is a draw with perfect play.