Solved Games and Opening Theory

For forty years, the best checkers player in the world was a soft-spoken mathematics professor named Marion Tinsley. Across his entire career he lost a handful of games — fewer than ten that mattered. He was, plausibly, the most dominant human in the history of any competitive game. In 1992 a program called Chinook, built by Jonathan Schaeffer’s team at the University of Alberta, challenged him; Tinsley won the match 4–2, and two of those four wins were among the rarest events in the sport. They met again in 1994. Six games in, all drawn, Tinsley withdrew, complaining of stomach pains. He was diagnosed with pancreatic cancer days later and died the next year.

In 2007, Schaeffer’s team finished the job Tinsley had stood in the way of: they solved checkers. After eighteen years of computation across hundreds of machines, they proved that from the opening position, with perfect play on both sides, the game is a draw. There is nothing left to discover. The book is closed.

Most games aren’t solved that cleanly — checkers and Connect Four (a first-player win, cracked in 1988) are unusual. What games develop instead is something looser and almost as powerful: theory. Generations of strong players accumulate the openings known to be good, the standard responses, the lines tried and refuted, until the early game is less a contest of invention than a recital of memorized best practice. Chess has libraries of opening theory; StarCraft has standard build orders. The community has, collectively, partly solved the game.

When a game is solved or near-solved, the question shifts. It stops being “what’s a good move?” and becomes “do you know the move already known to be good?”

This is a trap and a gift at once. The gift: you stand on accumulated knowledge instead of rediscovering it. No serious chess player reinvents the opening; they learn theory and start from the frontier. The trap: it’s easy to mistake knowing the theory for understanding the position. A player who has memorized twenty moves of a line but not grasped why each move is played collapses the moment the opponent deviates — he has the answers without the reasons.

This is the line between earned understanding and cargo cult. The cargo cult copies the form of expert play — the moves, the rituals — without the causal understanding that produced it, and it works right up until conditions change. Memorized theory is borrowed understanding. It pays off inside known territory and fails the instant you leave it.

There’s a deeper pattern about any field that matures. Early on the frontier is wide and a clever amateur can find genuinely new things. As theory piles up, the explored region grows, the easy discoveries get taken, and progress increasingly demands either mastering all prior theory first or finding the rare unexplored edge. The metagame “solves,” and creativity migrates to its margins — novelties, anti-theory, punishing opponents who know the book too rigidly to adapt.

Even the arrival of superhuman machines didn’t close it. When Deep Blue beat Garry Kasparov in 1997, people expected chess to wither; instead, engines became teachers, and human play got more creative as players raided the computer’s ideas. Maturity doesn’t kill creativity. It relocates it. An innovation in a solved-ish game isn’t a better opening move; it’s a move that’s worse by the book but better against a specific opponent, or a return to a line everyone had abandoned, now playable because the refutation was itself refuted.

The lesson for any well-trodden discipline: learn the theory, because reinventing it is waste — but learn it with its reasons, so you know which rules are load-bearing and which are mere convention. The player who understands why the book move is good is the one who knows when to leave the book. A solved game still has unsolved players. That’s where everything interesting now happens.

Go Deeper

Books

One Jump Ahead by Jonathan Schaeffer — Building Chinook, the rivalry with Tinsley, and what it took to solve checkers, by the man who did it.
Behind Deep Blue by Feng-hsiung Hsu — The inside story of the machine that beat a reigning world chess champion, by its chief architect.