John Isner has an impressive grass court record of 56–29 across 85 matches (65.9% — strong). A win rate of that calibre over 85 matches is a reliable indicator of genuine quality on this surface. 4 titles on grass: Newport — a record that reflects consistent ability to close out tournaments on this surface.

At Grand Slam level (Wimbledon): John Isner is 18–14 (56.3%) across 32 Grand Slam matches — below .500, though the elite draw depth at the Slams makes that a notoriously difficult barrier to crack.

4 finals reached on grass — converted 4 into titles (outstanding 100% conversion rate). Converting finals at that rate separates champions from contenders. 8 semifinals. 12 quarterfinals.

vs. Top 10 on grass: 1–4 (20.0%, 5 matches). Top 10 opponents have represented a clear ceiling on grass; addressing that deficit is the single biggest lever for improving the overall record here.

By format on grass — best-of-five: 20–14 (58.8%); best-of-three: 36–15 (70.6%). Markedly stronger in three-set formats; the win rate drops noticeably in five-setters, which has direct implications for Grand Slam performance on grass.

Best season: 2011 — 6–1 (85.7%) from 7 matches. The best single-season display to date — a useful reference point as the grass record continues to develop.

John Isner put together an impressive 9-match winning streak on grass, highlighting the ability to maintain high performance across multiple tournament rounds and events.