Denis Istomin has a competitive grass court record of 41–35 across 76 matches (53.9%). The record shows a player capable of competing here, though there is clear room to push the win rate higher. Claimed 1 title on grass: Nottingham.

At Grand Slam level (Wimbledon): Denis Istomin is 10–11 (47.6%) across 21 Grand Slam matches — below .500, though the elite draw depth at the Slams makes that a notoriously difficult barrier to crack.

One final reached on grass, converted into a title — a perfect finals record on this surface. 3 semifinals. 6 quarterfinals.

vs. Top 10 on grass: 0–4 (0.0%, 4 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: 12–13 (48.0%); best-of-three: 29–22 (56.9%). 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: 2015 — 6–2 (75.0%) from 8 matches. The best single-season display to date — a useful reference point as the grass record continues to develop.