Penny Birkhofer

Penny has been 4.0 for all 6 seasons on record, but moved a long way inside it — from the bottom of the band to the top.

The line is our estimate; the horizontal lines are level boundaries, so crossing one is a bump. Hollow points are years we inferred from the level played the following season, because USTA publishes a current rating but no history.

Percentile compares the same level in the same season, by share of games won. Mixed is shown for context — USTA rules exclude it from your adult rating unless mixed is all you play.

Games won matters more than matches won — NTRP adjusts on margins.

Signing in lets you point an account at your own record and keep things alongside it: notes on individual matches, your racquet and string setup, restring reminders, friendly matches that never reach TennisLink, and a diary of what you changed and what happened after.

None of it is visible to anyone else. Not to other players, not on your public page, not in search. Every private table is scoped to your account at the database level, so it is enforced rather than promised. The public page you are looking at is built from USTA match results and nothing else.