Lukas Dlouhy has found clay courts difficult, recording 13–26 across 39 matches (33.3%). 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): Lukas Dlouhy is 3–3 (50.0%) across 6 Grand Slam matches — below .500, though the elite draw depth at the Slams makes that a notoriously difficult barrier to crack.

By format on clay — best-of-five: 3–3 (50.0%); best-of-three: 10–23 (30.3%). Significantly better in five-set matches — a strong physical profile on clay that tends to tell as matches and tournaments progress.

Best season: 2005 — 3–3 (50.0%) from 6 matches. The best single-season display to date — a useful reference point as the clay record continues to develop.