Head to head
2
Hard
0
0
Clay
1
0
Grass
1
1
Carpet
0
Jan Siemerink's wins on the left · Sjeng Schalken's on the right · bar lengths share one scale
All meetings (5)
| 2001 | Amsterdam | Clay | R16 | Sjeng Schalken | 3-6 6-4 6-4 |
| 2001 | 's-Hertogenbosch | Grass | R32 | Sjeng Schalken | 6-3 6-4 |
| 2001 | Australian Open | Hard | R128 | Jan Siemerink | 2-6 6-3 6-4 3-6 6-3 |
| 1998 | Cincinnati Masters | Hard | R64 | Jan Siemerink | 1-6 6-1 7-6(2) |
| 1997 | Stuttgart Masters | Carpet | R64 | Jan Siemerink | 6-4 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.