Gilles Muller holds a solid grass court record of 45–36 across 81 matches (55.6%). A winning majority across 81 matches shows consistent ability to get results on grass. Claimed 1 title on grass: 's-Hertogenbosch.

At Grand Slam level (Wimbledon): Gilles Muller is 12–11 (52.2%) across 23 Grand Slam matches — below .500, though the elite draw depth at the Slams makes that a notoriously difficult barrier to crack.

3 finals reached on grass — won 1, lost 2 (33% conversion) — capable of reaching finals consistently, with room to improve at the decisive moment. 6 semifinals. 10 quarterfinals.

vs. Top 10 on grass: 4–6 (40.0%, 10 matches). Competitive against the elite, but still narrowly below .500 — closing that gap would directly elevate the overall grass court profile.

By format on grass — best-of-five: 12–11 (52.2%); best-of-three: 33–25 (56.9%). Slightly stronger in three-set contests on grass, though the five-set record is still respectable.

Best season: 2017 — 11–2 (84.6%) from 13 matches. The best single-season display to date — a useful reference point as the grass record continues to develop.