John Clifton has found grass courts difficult, recording 11–19 across 30 matches (36.7%). 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 (Wimbledon): John Clifton has struggled at Grand Slam level on grass: 1–6 (14.3%) in 7 matches. The best-of-five format and elite fields make this the toughest benchmark on this surface.

By format on grass — best-of-five: 1–6 (14.3%); best-of-three: 10–13 (43.5%). Markedly stronger in three-set formats; the win rate drops noticeably in five-setters, which has direct implications for Grand Slam performance on grass.

Best season: 1969 — 4–3 (57.1%) from 7 matches. The best single-season display to date — a useful reference point as the grass record continues to develop.