Head to head
2
Clay
0
1
Grass
0
John van Lottum's wins on the left · Jan Siemerink's on the right · bar lengths share one scale
All meetings (3)
| 1999 | 's-Hertogenbosch | Grass | R32 | John van Lottum | 6-4 4-6 6-3 |
| 1999 | Monte Carlo Masters | Clay | R64 | John van Lottum | 5-7 6-1 6-4 |
| 1998 | Roland Garros | Clay | R128 | John van Lottum | 6-7(5) 6-3 6-2 3-6 6-2 |
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.