Head to head
1
Clay
0
0
Carpet
1
Jaime Oncins's wins on the left · Mark Koevermans's on the right · bar lengths share one scale
All meetings (2)
| 1992 | Barcelona Olympics | Clay | R16 | Jaime Oncins | 7-6 6-0 7-6 |
| 1990 | Sao Paulo | Carpet | R32 | Mark Koevermans | 6-4 7-5 |
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.