Alex O'Brien has found clay courts difficult, recording 10–21 across 31 matches (32.3%). 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): Alex O'Brien 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: 2–4 (33.3%); best-of-three: 8–17 (32.0%). Consistent regardless of format on clay — a sign of a well-rounded game that holds up as matches develop.

Best season: 1993 — 4–3 (57.1%) from 7 matches. The best single-season display to date — a useful reference point as the clay record continues to develop.