PERA

Fair seeding,
audit-able rating.

PERA (Paired Elo Rating Adjustment) is HmBr's transparent rating algorithm. Confidence-weighted, format-specific, decay-aware. Every change is logged, every rating is auditable.

What makes PERA different

Five ideas. Hundreds of matches behind every number.

Confidence-weighted

Every rating ships with an uncertainty score (U). High-U ratings move faster after new results; low-U ratings stabilize. New players move fast — pros move slow. Same algorithm, different velocity.

Format-specific

Singles ≠ doubles ≠ mixed. Your serve-volley game in singles tells us nothing about how you set up your partner in mixed. Three independent ratings, no contamination.

Verified-court matches carry 3× weight

If your match was scored on a booked HmBr court with a chair umpire, it's worth 3× a casual rec match. Confidence interval visible on every profile so you always know how trustworthy a rating is.

Decay after 90 days

Inactivity decay starts at 90 days. Your rating drops 0.5 points per day after that, capped at -50 over a year. Stops the leaderboard from being haunted by ex-players.

Public + auditable

Every PERA change is logged with the match that caused it. You can audit your own rating history at any time. Algorithm is published in CLAUDE.md.

Live leaderboard

Top 10 · Men's Singles

Badminton
#
Player
Matches
Status
Rating
1
Player 9
Sunnyvale, CA
13
Provisional
1850
2
Organizer
Sunnyvale, CA
50
Provisional
1850
3
Arjun
1
Provisional
1806
4
Player 10
Sunnyvale, CA
38
Established
1780
5
Priya
0
Provisional
1770
6
Vikram
0
Provisional
1740
7
Player 2
Sunnyvale, CA
42
Provisional
1720
8
Neha
1
Provisional
1711
9
Player 14
Sunnyvale, CA
47
Established
1690
10
Rohan
1
Provisional
1679

Provisional ratings have fewer than 10 verified matches. Confidence interval visible on each profile.