Daniel Vacek defeated Jan Siemerink 7-6 7-6 in the Rotterdam round of 32 on hard. The result followed the form book — Daniel Vacek came in leading the head-to-head 2–0. Daniel Vacek extended the head-to-head to 3–0.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1998-08-24 | Long Island | R16 | hard | Daniel Vacek | 6-1 4-6 6-3 |
| 1998-08-10 | Cincinnati Masters | R16 | hard | Daniel Vacek | 6-1 6-4 |
Each player's serve crossed against the other's return, converted to expected hold of serve. Recent completed matches, ATP, WTA & Challenger. About
Averages over each player's completed matches in the selected window (181 vs 199). ATP, WTA & Challenger.