Head to head
0
Grass
1
1
Carpet
1
Byron Bertram's wins on the left · Nicholas Kalogeropoulos's on the right · bar lengths share one scale
All meetings (3)
| 1974 | Omaha | Carpet | R16 | Byron Bertram | 7-6 6-1 |
| 1973 | Washington-2 | Carpet | R16 | Nicholas Kalogeropoulos | 6-3 6-0 |
| 1970 | Beckenham | Grass | QF | Nicholas Kalogeropoulos | 6-4 6-1 |
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.