Jan Norback has found clay courts difficult, recording 12–33 across 45 matches (26.7%). 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): Jan Norback is 3–4 (42.9%) across 7 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: 4–3 (57.1%); best-of-three: 8–30 (21.1%). Significantly better in five-set matches — a strong physical profile on clay that tends to tell as matches and tournaments progress.

Best season: 1980 — 4–6 (40.0%) from 10 matches. The best single-season display to date — a useful reference point as the clay record continues to develop.