Playing conditions
Wind is the one condition that never stays the same from one point to the next. It makes serving harder, and the match data shows it: fewer aces and fewer service holds on windy days.
The serve starts with a ball thrown high into the air, and a gust can move it before the racket arrives. Players take the toss again, shorten it or play it safe, and a safer serve gives the returner more to work with.
With the wind behind, the ball carries deeper and is harder to keep in. Into the wind, it slows down and sits up. Across the court, it drifts. Most players aim further inside the lines in the wind, and that margin costs aces.
On calm days servers hit slightly more aces than at the same tournament on breezier days. Once the wind gets up to 25 km/h, aces drop by about 4% and serve is broken more often.
| Strongest wind of the day | Aces | Holds (pts) |
|---|---|---|
| Under 15 km/h | +1.8% | +0.2 |
| 15–24 km/h | -0.1% | 0.0 |
| 25–34 km/h | -3.9% | -0.5 |
| 35 km/h and up | -4.6% | -1.0 |
Each match is compared with the same tournament on its other days, so the court, the balls and most of the field stay the same. Outdoor ATP matches with serve statistics since 2019, venues below 550 m. Holds: the change in service games held, in percentage points.
Wind is measured in the open, 10 metres above the ground. A court sits lower and is often surrounded by stands, which shelter it, so the players feel less than the number in the forecast. Gusts are what they notice most: it's the change in wind, not the wind itself, that is hard to play.
DeepCourt's court speed reading measures how fast each tournament actually played, conditions included, so a windy week shows up in it.
How court speed is worked out