Jan Kukal has found grass courts difficult, recording 10–13 across 23 matches (43.5%). 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): Jan Kukal is 6–9 (40.0%) across 15 Grand Slam matches — below .500, though the elite draw depth at the Slams makes that a notoriously difficult barrier to crack.

By format on grass — best-of-five: 7–11 (38.9%); best-of-three: 3–2 (60.0%). 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: 1970 — 4–4 (50.0%) from 8 matches. The best single-season display to date — a useful reference point as the grass record continues to develop.