Felix Mantilla has an impressive clay court record of 235–122 across 357 matches (65.8% — strong). A win rate of that calibre over 357 matches is a reliable indicator of genuine quality on this surface. With 10 titles, among the most prolific clay court champions in the Open Era: Oporto, Bologna, Umag, San Marino and 5 more.

At Grand Slam level (Roland Garros): a positive 17–9 (65.4%) across 26 matches — a player who generally rises to the occasion at the Slams on clay.

ATP Masters 1000 on clay (Monte Carlo, Madrid, Rome): Felix Mantilla is elite here — 43–22 (66.2%) across 65 matches. Sustaining that win rate in the Tour's deepest regular-week draws is a defining quality of the very best on this surface.

18 finals reached on clay — won 10, lost 8 (solid 56% conversion) — consistently getting to finals and winning the majority is a hallmark of elite performers on clay. 29 semifinals. 49 quarterfinals.

vs. Top 10 on clay: 10–19 (34.5%, 29 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: 20–11 (64.5%); best-of-three: 215–111 (66.0%). Consistent regardless of format on clay — a sign of a well-rounded game that holds up as matches develop.

Dominant season: 1997 — 42–8 (84.0%) from 50 matches. A campaign of 42 wins on clay in a single season is among the best single-season records the surface has seen — the clearest benchmark of what is achievable at peak level.