12-Team MLB Playoff Format: The top 2 division winners in each league earn byes to the Division Series (DS). Seeds 3 through 6 square off in a high-stakes, best-of-three Wild Card Series hosted entirely at the higher seed's home park.

Pythagorean Win Expectancy & Log5 Matchups: Individual game win probabilities are derived from Bill James' log5 equation adjusted for each club's regular season run differential, wRC+ offensive index, starting rotation FIP, and late-inning bullpen leverage index.

Monte Carlo Simulation: When running the 10,000-run simulation, each series is simulated pitch-by-pitch and game-by-game across full bracket permutations, incorporating rest days and rotation sequencing to calculate genuine championship odds.

Local Execution & Export: All calculations, probability matrices, and bracket states run entirely inside your browser. Export the populated bracket state as a JSON report or use presets to test underdog Cinderella runs.