Ivo Karlovic has found clay courts difficult, recording 55–76 across 131 matches (42.0%). The numbers point to a surface that has not consistently suited the game — a key area of opportunity on the calendar. Claimed 1 title on clay: Houston.

At Grand Slam level (Roland Garros): Ivo Karlovic has struggled at Grand Slam level on clay: 8–14 (36.4%) in 22 matches. The best-of-five format and elite fields make this the toughest benchmark on this surface.

ATP Masters 1000 on clay (Monte Carlo, Madrid, Rome): Ivo Karlovic is 13–21 (38.2%) across 34 Masters matches — below .500 in the Tour's deepest fields. Lifting that record here would unlock better results across the whole clay swing.

3 finals reached on clay — won 1, lost 2 (33% conversion) — capable of reaching finals consistently, with room to improve at the decisive moment. 6 semifinals. 10 quarterfinals.

vs. Top 10 on clay: 3–10 (23.1%, 13 matches). Top 10 opponents have represented a clear ceiling on clay; addressing that deficit is the single biggest lever for improving the overall record here.

By format on clay — best-of-five: 9–18 (33.3%); best-of-three: 46–58 (44.2%). Markedly stronger in three-set formats; the win rate drops noticeably in five-setters, which has direct implications for Grand Slam performance on clay.

Best season: 2007 — 5–2 (71.4%) from 7 matches. The best single-season display to date — a useful reference point as the clay record continues to develop.