Hans-Joachim Ploetz has found clay courts difficult, recording 49–60 across 109 matches (45.0%). The numbers point to a surface that has not consistently suited the game — a key area of opportunity on the calendar. Hans-Joachim Ploetz has reached 1 final without yet claiming a title on clay — one of the finest margins in tennis.

At Grand Slam level (Roland Garros): Hans-Joachim Ploetz has struggled at Grand Slam level on clay: 3–5 (37.5%) in 8 matches. The best-of-five format and elite fields make this the toughest benchmark on this surface.

One final reached on clay, without converting it into a title. That final-round experience is valuable groundwork for going one step further next time. 3 semifinals. 8 quarterfinals.

vs. Top 10 on clay: 1–2 (33.3%, 3 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: 10–18 (35.7%); best-of-three: 39–42 (48.1%). Markedly stronger in three-set formats; the win rate drops noticeably in five-setters, which has direct implications for Grand Slam performance on clay.

Peak season: 1969 — 15–10 (60.0%) from 25 matches. That year captures the ceiling of what Hans-Joachim Ploetz can do on clay when performing at their best and represents the standard to aim for.