Lukas Klein has found hard courts difficult, recording 6–15 across 21 matches (28.6%). 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 (Australian Open & US Open): 1–2 across just 3 matches — still very early days at this level on hard.

ATP Masters 1000 on hard (Indian Wells, Miami, Canada, Cincinnati, Shanghai, Paris): Lukas Klein has struggled at Masters level on hard: 1–2 (33.3%) in 3 matches. Improving at this level is the clearest path to a stronger overall record on this surface.

vs. Top 10 on hard: 0–3 (0.0%, 3 matches). Top 10 opponents have represented a clear ceiling on hard; addressing that deficit is the single biggest lever for improving the overall record here.

By format on hard — best-of-five: 1–2 (33.3%); best-of-three: 5–13 (27.8%). Slightly better in five-set matches on hard — a positive sign for the Slams specifically.

Best season: 2024 — 6–8 (42.9%) from 14 matches. The best single-season display to date — a useful reference point as the hard record continues to develop.