Why most amateurs track the wrong stats
Counting winners in your own match is unreliable: you forget, you exaggerate, and the rally context disappears. The good news is that the stats that do matter — holds, breaks, serve percentages, opponent splits — can be derived almost entirely from a clean game-by-game scoreline.
Hold % and break %
The two most predictive numbers in amateur tennis. Hold % is the share of your service games you win; break % is the share of your opponent's service games you win. A healthy intermediate player holds 60–75% and breaks 25–40%. If hold drops below 50%, fix the serve first; if break is below 20%, work on return positioning and second-serve attack.
First-serve percentage
Aim for 60–65% in, points won behind first serve above 65%, and behind second serve above 45%. Below those, the serve is a liability.
Win rate trends — not snapshots
A single win rate number is meaningless without context. Read it as a rolling line over your last 5, 10 and 20 matches. A flat 50% line with high variance hides more information than a smooth climb from 40% to 55%.
Opponent splits and head-to-head
Tennis is matchup-driven. Track win rate per opponent and per surface — the patterns (struggle vs lefties, dominate on clay) emerge after 20–30 matches.
Heart-rate zones from your smartwatch
Time in Zone 4–5 is a proxy for match intensity. Comparing a win vs a loss at similar duration tells you whether intensity, not skill, decided the outcome.
How to record this efficiently
Log scores game-by-game right after the match. Everything else is derived. Tennis Log does this in roughly 90 seconds per match.