Head to head
1
Hard
1
0
Carpet
2
Jan Siemerink's wins on the left · Karol Kucera's on the right · bar lengths share one scale
All meetings (4)
| 1998 | New Haven | Hard | R16 | Karol Kucera | 6-4 7-5 |
| 1996 | Los Angeles | Hard | R32 | Jan Siemerink | 6-3 7-6(5) |
| 1995 | Moscow | Carpet | R32 | Karol Kucera | 4-6 7-5 7-5 |
| 1995 | Copenhagen | Carpet | QF | Karol Kucera | 6-4 6-4 |
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.