Ulrich Marten has found clay courts difficult, recording 7–25 across 32 matches (21.9%). 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): 1–1 across just 2 matches — still very early days at this level on clay.

Best season: 1980 — 5–6 (45.5%) from 11 matches. The best single-season display to date — a useful reference point as the clay record continues to develop.