Pietro Marzano has found clay courts difficult, recording 5–16 across 21 matches (23.8%). The numbers point to a surface that has not consistently suited the game — a key area of opportunity on the calendar.

At Grand Slam level (Roland Garros): Pietro Marzano is 2–2 (50.0%) across 4 Grand Slam matches — below .500, though the elite draw depth at the Slams makes that a notoriously difficult barrier to crack.

By format on clay — best-of-five: 2–2 (50.0%); best-of-three: 3–14 (17.6%). Significantly better in five-set matches — a strong physical profile on clay that tends to tell as matches and tournaments progress.