Marcos Ondruska has a competitive clay court record of 27–33 across 60 matches (45.0%). The record shows a player capable of competing here, though there is clear room to push the win rate higher. Marcos Ondruska has reached 1 final without yet claiming a title on clay — one of the finest margins in tennis.

At Grand Slam level (Roland Garros): Marcos Ondruska is 5–7 (41.7%) across 12 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 clay (Monte Carlo, Madrid, Rome): Marcos Ondruska is 3–4 (42.9%) across 7 Masters matches — below .500 in the Tour's deepest fields. Lifting that record here would unlock better results across the whole clay swing.

One final reached on clay, without converting it into a title. That final-round experience is valuable groundwork for going one step further next time. 2 semifinals. 4 quarterfinals.

vs. Top 10 on clay: 1–6 (14.3%, 7 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: 6–10 (37.5%); best-of-three: 21–23 (47.7%). 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: 1992 — 4–1 (80.0%) from 5 matches. The best single-season display to date — a useful reference point as the clay record continues to develop.