Henry Pfister has found clay courts difficult, recording 24–31 across 55 matches (43.6%). 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): Henry Pfister has struggled at Grand Slam level on clay: 1–5 (16.7%) in 6 matches. The best-of-five format and elite fields make this the toughest benchmark on this surface.

vs. Top 10 on clay: 0–6 (0.0%, 6 matches). Top 10 opponents have represented a clear ceiling on clay; addressing that deficit is the single biggest lever for improving the overall record here.

By format on clay — best-of-five: 1–4 (20.0%); best-of-three: 23–27 (46.0%). Markedly stronger in three-set formats; the win rate drops noticeably in five-setters, which has direct implications for Grand Slam performance on clay.

Best season: 1977 — 10–8 (55.6%) from 18 matches. The best single-season display to date — a useful reference point as the clay record continues to develop.