John Yuill has found clay courts difficult, recording 45–72 across 117 matches (38.5%). 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): John Yuill is 11–10 (52.4%) across 21 Grand Slam matches — below .500, though the elite draw depth at the Slams makes that a notoriously difficult barrier to crack.

vs. Top 10 on clay: 0–8 (0.0%, 8 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: 4–6 (40.0%); best-of-three: 41–66 (38.3%). Consistent regardless of format on clay — a sign of a well-rounded game that holds up as matches develop.

Best season: 1974 — 9–5 (64.3%) from 14 matches. The best single-season display to date — a useful reference point as the clay record continues to develop.