Cecil Mamiit has found clay courts difficult, recording 7–16 across 23 matches (30.4%). The numbers point to a surface that has not consistently suited the game — a key area of opportunity on the calendar.

At Grand Slam level (Roland Garros): Cecil Mamiit has struggled at Grand Slam level on clay: 2–4 (33.3%) in 6 matches. The best-of-five format and elite fields make this the toughest benchmark on this surface.

By format on clay — best-of-five: 5–9 (35.7%); best-of-three: 2–7 (22.2%). Significantly better in five-set matches — a strong physical profile on clay that tends to tell as matches and tournaments progress.

Best season: 1999 — 2–3 (40.0%) from 5 matches. The best single-season display to date — a useful reference point as the clay record continues to develop.