Marcelo Rios has a competitive grass court record of 6–6 across 12 matches (50.0%). The record shows a player capable of competing here, though there is clear room to push the win rate higher.

At Grand Slam level (Wimbledon): Marcelo Rios is 3–3 (50.0%) across 6 Grand Slam matches — below .500, though the elite draw depth at the Slams makes that a notoriously difficult barrier to crack.

By format on grass — best-of-five: 5–3 (62.5%); best-of-three: 1–3 (25.0%). Significantly better in five-set matches — a strong physical profile on grass that tends to tell as matches and tournaments progress.

Best season: 1997 — 5–2 (71.4%) from 7 matches. The best single-season display to date — a useful reference point as the grass record continues to develop.