Head to head
0
Clay
1
1
Grass
0
John Marks's wins on the left · Jose-Luis Clerc's on the right · bar lengths share one scale
All meetings (2)
| 1978 | Australian Open | Grass | R64 | John Marks | 6-7 RET |
| 1978 | Boston | Clay | R32 | Jose-Luis Clerc | 6-1 6-3 |
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.