The most advanced baseball simulation, built for the browser.
Simulation Baseball is a next-generation baseball management game. You run an entire front office and watch every game resolve one pitch at a time, on an engine built from the modern game up. Play solo against thinking AI general managers, or share a league with up to 30 real people. No download, no install. It runs in any browser.
Every pitch, simulated
The engine plays the game pitch by pitch, not a box-score shortcut. Every plate appearance is a real confrontation: the pitcher's arsenal against the hitter's swing decisions, in that park, that count, that leverage. And it is deterministic. The same inputs always produce the same game, so any result can be replayed pitch for pitch and trusted, never hand-waved.
Statcast-grade ratings
Players are not four blurry stars. Every pitcher carries a real arsenal, fastball, slider, curve, change, cutter, sweeper, each with its own velocity, induced vertical and horizontal break, approach angle, and spin. Every hitter carries bat speed, swing decisions, an exit-velocity distribution, and a barrel rate. These are ratings that map cleanly to how the game is actually measured today, the same vocabulary a modern front office speaks.
Modern baseball, by default
The numbers that run real front offices lead the interface: wRC+, FIP, xwOBA, Stuff+, K-BB%, surplus value. Heat maps, spray charts, and pitch-arsenal visuals instead of a wall of AVG, HR, and RBI. And the whole engine is calibrated against real Statcast-era data, so platoon splits, run environment, aging curves, and batted-ball variance behave like the real thing. We re-validate it against real league baselines on every build.
AI that actually knows baseball
Every open seat is run by AI that plays by modern logic, not save-rule reflexes. It leverages its bullpen by situation, sets platoon-aware lineups, pulls a starter at the third-time-through-the-order penalty, and values trades on surplus value rather than name recognition. Each AI general manager has its own temperament. And a built-in assistant explains the why, right where you make the call, flagging regression candidates, leverage mistakes, and the platoon edge you are about to leave on the bench.
Live, online, and yours on any screen
SimBB is one live, server-authoritative league, not a save file you email around. Trades execute the instant they are accepted. Play on a laptop at your desk and a phone on the bus, the same league, always current. Up to 30 real general managers share a world, and the engine's own AI seamlessly fills any open seat without ever taking one a human wants.
Open where it counts
Most sims keep the engine a black box where ratings go in and outcomes come out by magic. We do not. The mechanics are documented and the data is queryable, so a front-office question that used to mean scraping two dozen pages gets answered in one. You can always see why a number is what it is, which is exactly what the analytics-minded crowd has been reverse-engineering by hand for years.
The whole front office
Scout and draft, work international free agency, trade, sign free agents, negotiate extensions and arbitration, run the farm system, set lineups, rotations and depth charts, hire your coaching staff, and manage the budget and the owner who signs the checks. Then advance the season and watch it play out. It is as deep as the sim it is built to beat, without the install, the file-passing, or the 2010-era menus.
The beta
Simulation Baseball is targeting a Fall 2026 launch and the beta is free. Join the waitlist for a heads up when it is ready to play ball.
Get in touch
Email [email protected], or find us on Instagram, YouTube, Reddit, LinkedIn, and Facebook.