MMR Calculation

1. What is MMR?

MMR (Matchmaking Rating) is a skill score that moves after every eligible game. The system compares your actual result against your expected result, then applies context factors to compute your final MMR change.

2. Solo, Duo, and Team MMR are separated

Your rating is stored per player and per mode. This means solo MMR, duo MMR, and team MMR are independent tracks. A result in one mode does not directly change the other modes.

3. When does a game count for MMR?

MMR is computed per game, not just per match. Games only count when a match is finalized and passes eligibility checks (for example, valid ranked roster data and tournament MMR eligibility settings).

4. Core MMR calculation (simplified)

We compute expected win chance from relative strength first, then scale the change using performance and reliability factors.

Rating changes are computed from expected result vs actual result, then adjusted by contribution and reliability factors with per-game caps to prevent extreme swings.

Expected result and strength are mode-aware:

• Solo: player strength compared with lobby or opponent pool.
• Duo: pair strength compared against opposing duo strength.
• Team: overall team strength based on the players in that game.

5. What factors affect each game's MMR?

• Relative strength: stronger-vs-weaker matchups produce smaller gains for expected winners and larger gains for underdogs that upset.
• Game result and rank: better placement or higher contribution generally increases positive movement.
• Individual contribution: your own in-game output matters, so teammates can move by different amounts.
• Reliability/provisional status: early games are more volatile, then movement stabilizes as confidence increases.
• Match context: format/importance can scale movement.
• Anti-abuse controls: repeat pairing or edge-case patterns can be dampened by adjustment factors.

6. Strong vs weak: what happens?

• Strong beats weak (as expected): small MMR gain, and weak-quality wins can be reduced further by quality penalty.
• Weak beats strong (upset): higher MMR boost for weak side, higher drop for strong side.
• Strong beats weak but only by slight luck/low-quality performance: gain can be very small, zero, or even slightly negative after context factors.

7. Why new players move faster (provisional period)

New players have less certainty, so the system allows larger movement early to find their correct level faster. After enough eligible games, rating changes become steadier.

You must complete at least 10 eligible games in professional tournaments to unlock visible MMR on public player surfaces.

8. Quick Notes