Cliff Letcher has found clay courts difficult, recording 15–42 across 57 matches (26.3%). 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): Cliff Letcher has yet to record a win on clay at this stage — 0–3 across 3 Grand Slam matches. Breaking through here would mark a significant step forward on this surface.

4 quarterfinals on clay, including one run to the semifinal — regularly reaching that stage is a solid baseline, with the next step being to break through to the final rounds more often.

vs. Top 10 on clay: 0–7 (0.0%, 7 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.

Best season: 1977 — 5–10 (33.3%) from 15 matches. The best single-season display to date — a useful reference point as the clay record continues to develop.