Stefan Koubek has found hard courts difficult, recording 97–121 across 218 matches (44.5%). The numbers point to a surface that has not consistently suited the game — a key area of opportunity on the calendar. Claimed 2 titles on hard: Delray Beach, Doha.

At Grand Slam level (Australian Open & US Open): Stefan Koubek is 18–19 (48.6%) across 37 Grand Slam matches — below .500, though the elite draw depth at the Slams makes that a notoriously difficult barrier to crack.

ATP Masters 1000 on hard (Indian Wells, Miami, Canada, Cincinnati, Shanghai, Paris): Stefan Koubek is 14–26 (35.0%) across 40 Masters matches — below .500 in the Tour's deepest fields. Lifting that record here would unlock better results across the whole hard swing.

3 finals reached on hard — won 2, lost 1 (solid 67% conversion) — consistently getting to finals and winning the majority is a hallmark of elite performers on hard. 5 semifinals. 15 quarterfinals.

vs. Top 10 on hard: 4–20 (16.7%, 24 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: 20–22 (47.6%); best-of-three: 77–99 (43.8%). Slightly better in five-set matches on hard — a positive sign for the Slams specifically.

Best season: 2006 — 6–4 (60.0%) from 10 matches. The best single-season display to date — a useful reference point as the hard record continues to develop.