A single number that tells you who is actually the best player in the office — not just who picked the easiest opponents.
Every office ladder that starts with a whiteboard tally runs into the same problem: a 12–2 record looks unbeatable until you notice all fourteen matches were against the same two beginners. Meanwhile the person who keeps challenging the office champion sits at 5–9 and looks mediocre.
Elo treats every match as a transfer of points between two players. Before the match, the system converts the rating gap into an expected result. If you were expected to win and you do, you collect very few points. If you were expected to lose and you win anyway, you collect a lot — and your opponent loses exactly the same amount.
Because points always come out of the loser's rating and go into the winner's, the office total stays balanced. Nobody can inflate their rating by farming beginners: each win against a much weaker player is worth close to nothing.
Priya is rated 1200. Marcus, the reigning office champion, is rated 1400. The 200-point gap means Marcus is expected to win about 76% of the time — Priya's expected score is roughly 0.24.
Elo converts that 200-point gap into a win probability using the formula 1 ÷ (1 + 10−rating gap ÷ 400). For Marcus, that is 1 ÷ (1 + 10−200/400) ≈ 0.76, or about 76%. The 400 in the formula is a constant that makes a 400-point gap equal to roughly a 90% expected win rate, so every 100-point gap is meaningful.
The 32 is the K-factor, a setting that controls how fast ratings change after each match. A K-factor of 32 means a single win or loss can move a rating by up to about 32 points. We chose it because it is responsive enough to show improvement within a few games, but not so jumpy that one lucky win rewires the whole ladder. It is the same value used by most office and casual sports ladders.
Actual score: 1 · Expected: 0.24
Change: 32 × (1 − 0.24) ≈ +24 points
Priya: 1200 → 1224
Marcus: 1400 → 1376
Actual score: 1 · Expected: 0.76
Change: 32 × (1 − 0.76) ≈ +8 points
Marcus: 1400 → 1408
Priya: 1200 → 1192
One upset moves Priya three times further than a routine win would move Marcus. That asymmetry is the whole point: the ladder reorders itself quickly when someone is underrated, and slowly when results confirm what everyone already knew.
Everyone joins at 1200. The number itself is arbitrary — what matters is the distance between players. A typical office settles into a spread from about 1050 for newcomers to 1400+ for the two or three people who played competitively at some point.
Learning the game, still finding consistency
The middle of most offices — competitive, streaky
Reliable spin and placement; the ones to beat
Start free, record your first match, and watch the ratings sort themselves out.