Invite-only beta · now open
Scouting, the draft, trades, free agency, the farm system. You make the calls and the engine plays every game out to a full box score. It runs in a browser, on a phone or a desktop, with nothing to install.
One email when your seat is ready. Nothing else.
The desk
There is no mode where the game plays the front office for you. Delegate what you want to delegate; the rest lands on your desk.
The engine
That is a big claim, so here is what is behind it. Most sims roll a number against a rating. This one plays out the confrontation.
Eight personality traits: intelligence, work ethic, greed, loyalty, leadership, wanting to play for a winner, adaptability, and a taste for controversy. They move what you would expect them to move. A smart pitcher and a smart catcher execute more of the game plan. A greedy one costs more in free agency. Morale runs off seven drivers, and a player far enough underwater asks out.
Which pitch gets thrown is eighteen of them: the count, his repertoire and how he likes to use it, what this hitter does to that pitch family, his fatigue, how many times he has already faced this lineup, and the leverage of the moment, which is itself computed from the inning, the outs, all three bases and both scores. What the pitch physically does is thirteen more: his stuff sets the velocity, his movement sets the break, his command sets how far it scatters from where he aimed. Then the catcher can steal a strike, and the park has an opinion.
A four-seamer, a sinker, a cutter, a slider, a curve, a knuckle-curve, a screwball, a change, a splitter, a forkball, a circle change, a knuckleball. Each carries its own velocity band and its own vertical and horizontal break, so a sinker moves like a sinker and a knuckleball is genuinely chaotic. Location lands in the same thirteen zones Statcast uses.
Every ball in play gets an exit velocity, a launch angle, a spray angle, a distance and a hang time. Hard-hit is 95 mph because that is what hard-hit means. The whole batted-ball model is calibrated against roughly 1.1 million real batted balls from 2015 to 2024, and a dedicated check refuses the build if the league that comes out does not look like the league that went in.
Defense is not a team rating that nudges a batting average. Nine fielders occupy real coordinates and each has range, arm and error. A ball in the 5.5 hole is an out to a rangy shortstop and a single to a statue. A gapper one center fielder cuts off for a double, another lets roll for a triple.
Sixty-six named ratings per player before you count his arsenal. Seven owner archetypes who authorize very different payrolls on the same revenue, five manager archetypes, eight coaching seats, and rival general managers who each value the same player differently. Scouting is fogged, so nobody sees true ratings but you, and not even you see them on other teams.
Calibrated against 155 seasons of Major League history, 1871 to 2025
The beta
A league is only as good as the managers in it, so seats go out in waves rather than one at a time. Beta is free, there is nothing to buy, and your league history carries forward to launch.
One email address. That is the whole form.
Invites go out in waves so a new league fills with real managers at once.
Start a solo league or claim a seat in one that is already running.
Questions
Simulation Baseball is a browser-based baseball franchise simulator. You run the whole front office: scouting, the draft, trades, free agency, the farm system, player development. A purpose-built engine plays every game out to play-by-play and box scores. Play solo against AI front offices, or join a league where all 30 general manager seats are real people.
The beta is invite-only and it is open. Request an invite at simulationbaseball.com with your email address and you go into the next wave. Invites go out in batches so new leagues start with a full complement of managers rather than trickling in.
A league is only as good as the managers in it. Inviting in waves means a new league fills with real people at the same time, and it keeps the number of live leagues at a size the team can actually watch while the engine is still being tuned.
Beta access is free. There are no microtransactions and no pay-to-win mechanics. Pricing after launch has not been announced.
Simulation Baseball is targeting a Fall 2026 launch. The invite-only beta is running now and beta managers keep their league histories.
No. Simulation Baseball runs entirely in your browser on desktop and mobile. There is nothing to install, no plugin, and no file to pass between managers.
Both. Run a single-player franchise against AI front offices, or join an online league of up to 30 human managers with AI covering any open seat. If a manager leaves mid-season the AI takes that seat and hands it back when someone claims it.
Deeply, and the honest answer is longer than one line. Thirty-three separate inputs decide a single pitch. Eighteen of them choose which pitch gets thrown: the count, his repertoire and how he likes to use it, what this hitter does to that pitch family, his fatigue, how many times he has already seen this lineup, his pitching coach, and the leverage of the moment, which is itself computed from the inning, the outs, all three bases and both scores. Thirteen more decide what the pitch physically does: stuff sets velocity, movement sets break, command sets how far it scatters from the target, handedness mirrors the whole shape. Then the catcher can steal or lose a strike, and the ballpark has an opinion. Around that pitch sits everything else. Twelve pitch types with their own velocity bands and break. Thirteen location zones, the same ones Statcast uses. Every ball in play carries an exit velocity, launch angle, spray angle, distance and hang time, calibrated against roughly 1.1 million real batted balls. Nine fielders at real coordinates with their own range, arm and error. Sixty-six named ratings per player, including eight personality traits that actually move outcomes: a smart pitcher and a smart catcher execute more of the game plan, a greedy one costs more in free agency, and a player whose morale falls far enough asks out. Morale runs off seven drivers and clubhouse chemistry rides on top of it. Every park carries its own outfield distances and wall heights in seven directions plus twelve months of real climate, so the ball carries differently in July than in April. And scouting is fogged, so nobody sees true ratings, including you on other teams.
Yes. Your league is stored as a linked chain of everything that has happened rather than a save file you could edit, so a rewritten history fails its own check and refuses to load. The same league replayed on another machine produces exactly the same results, which is why a disputed game can simply be replayed instead of argued about.
Yes. The default is a generated player universe with a realistic rating distribution, and any roster can be imported from CSV or JSON. Exports from other franchise sims work too; their column conventions are mapped on the way in.
The same depth of front-office and play-by-play simulation, entirely in a browser, with real-time online leagues and nothing to install. Trades execute the moment both sides accept instead of waiting on a commissioner to process a file, and the game works the same on a phone as on a desktop.