Head to head
4
Hard
1
1
Clay
0
1
Carpet
0
Andre Agassi's wins on the left · Jan Siemerink's on the right · bar lengths share one scale
Momentum
Running lead across all meetings, oldest to newest (walkovers excluded).
All meetings (7)
| 1999 | Basel | Carpet | R32 | Andre Agassi | 6-3 6-4 |
| 1998 | Adelaide | Hard | R16 | Andre Agassi | 6-4 6-3 |
| 1997 | Davis Cup WG QF: USA vs NED | Hard | RR | Andre Agassi | 3-6 3-6 6-3 6-3 6-3 |
| 1996 | US Open | Hard | R32 | Andre Agassi | 6-4 6-2 7-6(7) |
| 1996 | Monte Carlo Masters | Clay | R32 | Andre Agassi | 6-2 6-3 |
| 1994 | New Haven | Hard | R32 | Jan Siemerink | 6-3 3-6 6-3 |
| 1992 | US Open | Hard | R32 | Andre Agassi | 6-2 6-3 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.