Head to head
1
Hard
2
1
Clay
0
1
Grass
0
2
Carpet
1
Clark Graebner's wins on the left · Thomaz Koch's on the right · bar lengths share one scale
Momentum
Running lead across all meetings, oldest to newest (walkovers excluded).
All meetings (8)
| 1972 | Bristol | Grass | R16 | Clark Graebner | 6-1 4-6 7-5 |
| 1972 | Roland Garros | Clay | R64 | Clark Graebner | 6-2 6-0 6-2 |
| 1971 | Macon | Carpet | QF | Clark Graebner | 6-2 3-6 7-5 |
| 1970 | Berkeley | Hard | R16 | Thomaz Koch | 6-3 6-1 |
| 1970 | Hampton | Carpet | SF | Thomaz Koch | 4-6 10-8 4-6 6-3 6-3 |
| 1970 | Omaha | Hard | QF | Thomaz Koch | 9-7 6-1 |
| 1969 | Richmond | Carpet | F | Clark Graebner | 6-3 10-12 9-7 |
| 1968 | Bloemfontein | Hard | QF | Clark Graebner | 6-8 6-2 6-1 |
Methodology
Head-to-head totals and surface splits exclude walkovers (no match was played), which follows ATP convention — walkover meetings still appear in the match list. The momentum chart plots the running lead across all counted meetings, oldest to newest.