each one teaches you something. most of them also beat you.
Block-based natural deduction in seven books: propositions, all and some, equals, numbers, sets, divisibility and order.
3,282 lines propositional logic Lean 4 codegenThe oldest solved game. Lose to a perfect opponent, find its rule yourself, then read the 1901 proof annotated with your own moves.
combinatorial games Bouton 1901 built: perfect-play engine, proof replay from your movesDefine a continuous map with no fixed point. Brouwer's theorem says you can't.
topology Brouwer's theorem built: canvas function plotter, 1D/2D/annulusDivide a cake so nobody envies anyone. Eight levels of increasingly impossible fairness.
fair division PPAD built: envy-free allocation engine, 1130 linesIterated prisoner's dilemma. Play against classic strategies or run a tournament.
game theory Axelrod 1984 built: 6 strategy AIs + round-robin tournament20 candidates, one hire, no going back. When do you stop looking?
optimal stopping 1/e built: optimal threshold simulator, 809 linesDraft a VCT roster from real pros, play a single-elimination tournament. Economy management with VLR.gg data.
economy management VLR.gg data built: snake draft, bracket sim, pro ratingsYou are the regression. Drag a line through noise, get scored against OLS. Then Anscombe strikes.
regression Anscombe's quartet built: OLS engine + Anscombe dataset, 964 linesWill a drunk man find his way home? Will a drunk bird? Depends on the dimension.
random walks Polya 1921 built: WebGL 3D walker, batch convergence plotsA step-through tour of large numbers. Shuffled decks, chess games, Graham's number, TREE(3), and the busy beaver.
combinatorics computabilitySix tests of mathematical intuition. Estimation, sequences, functions, mental math, and pattern memory.
6 tests composite score