What it is
The Boxing Sim is a fight engine with a front page. You pick two boxers, set the distance, and the engine fights the bout round by round: knockdowns, cuts, a corner that might throw the towel, three judges who do not always agree. On top of that engine sit two long games, a career that takes a prospect from the amateurs to a world title and a stable you run from the manager’s desk, and a hub that lists what is on the card.
Everything is free and nothing installs. There is no account; a career or a promotion is saved in the browser you started it in.
The roster
Three hundred professional boxers, past and present, across every division from minimumweight to heavyweight plus five women's divisions. Each one carries twelve ratings, from power and hand speed to chin, stamina and ring IQ, plus the tale of the tape: height, reach, stance, record and titles. The ratings are ours. They come from watching how a boxer actually fights and from the record, the opposition and the knockout ratio, and they are argued over and revised. They are not official statistics, and we say so on every page that shows one.
Legends are rated in their prime. Robinson at 160 is the Robinson who beat LaMotta and Basilio, not the man who fought into his forties; a dream fight across eras is always prime against prime.
The engine
The engine does not average two numbers and pick the bigger. It scores each round the way a judge would, weighs power against the other man's chin and defense for the one punch that ends a fight, pays for work rate out of stamina in the late rounds, prices a size difference by the pound when boxers from different divisions meet, and gives a southpaw his awkwardness against an orthodox opponent who rarely sees one. Ring size, a late-replacement camp, a drained weigh-in, ring rust and a hometown crowd are all levers you can pull, and each one moves the result the way it moves a real fight.
Run the same fight a hundred times and you get a shape rather than a coin toss: how often each man wins, how the fights end, and in which rounds.
Why it is free
Because the arguments are the point. A fight game behind a paywall settles nothing; the value of this one is that anybody can pull up Ali against Tyson, or Inoue against Hamed, and have something concrete to argue about. The site carries ordinary advertising to pay for the server and the AI analysis, and that is all.
Who
The Boxing Sim is made by a small independent team of boxing fans. We are not connected to any sanctioning body, promoter, broadcaster, gym or boxer, and no boxer has endorsed a rating here. If you think we have someone wrong, the contact page is the place to say so; corrections with a reason attached get looked at first.
The name
Boxer, Sim. It says what it is. The blackletter and the aged paper are a nod to the fight pages that used to carry this kind of argument every Monday morning.