Head to head
1
Clay
5
0
Grass
2
1
Carpet
2
John Alexander's wins on the left · Tom Okker's on the right · bar lengths share one scale
Momentum
Running lead across all meetings, oldest to newest (walkovers excluded).
All meetings (11)
| 1974 | Toronto-2 | Clay | R16 | Tom Okker | 7-6 7-5 |
| 1974 | Toronto WCT | Carpet | SF | Tom Okker | 7-6(3) 6-2 |
| 1973 | Seattle | Carpet | F | Tom Okker | 7-5 6-4 |
| 1972 | Louisville WCT | Clay | R16 | Tom Okker | 7-6 2-6 6-3 |
| 1972 | Charlotte WCT | Clay | QF | John Alexander | 6-2 6-4 |
| 1972 | Houston WCT | Clay | QF | Tom Okker | 7-6 6-4 |
| 1971 | Louisville WCT | Clay | QF | Tom Okker | 6-1 4-6 6-2 |
| 1970 | Wembley | Carpet | R32 | John Alexander | 6-2 9-8 |
| 1970 | Hamburg | Clay | R16 | Tom Okker | 6-3 6-2 6-1 |
| 1970 | Auckland | Grass | QF | Tom Okker | 6-4 6-4 6-4 |
| 1970 | Australian Open | Grass | R16 | Tom Okker | 7-5 10-8 10-12 4-6 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.