Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Outcome | No. | Date | Tournament | Surface | Partner | Opponents in the final | Score in the final |
| --- | --- | --- | --- | --- | --- | --- | --- |
| Runner-up | 1. | 1972 | Stockholm, Sweden | Hard (i) | Roy Emerson | Tom Okker\n Marty Riessen | 5–7, 6–7 |
| Runner-up | 2. | 1973 | Miami WCT, US | Hard | Terry Addison | Roy Emerson\n Rod Laver | 4–6, 4–6 |
| Runner-up | 3. | 1973 | Richmond WCT, US | Carpet | Terry Addison | Roy Emerson\n Rod Laver | 6–3, 3–6, 4–6 |
| Runner-up | 4. | 1973 | St. Louis, US | Carpet | Terry Addison | Ove Nils Bengtson\n Jim McManus | 2–6, 5–7 |
| Runner-up | 5. | 1973 | Columbus, US | Hard | Charles Pasarell | Gerald Battrick\n Graham Stilwell | 4–6, 6–7 |
| Winner | 1. | 1973 | Merion, US | Grass | Allan Stone | John Austin\n Fred McNair | 7–6, 6–3 |
| Runner-up | 6. | 1973 | Tokyo Outdoor |  | Allan Stone | Mal Anderson\n Ken Rosewall | 5–7, 5–7 |
| Winner | 2. | 1973 | Hong Kong | Hard | Rod Laver | Paul Gerken\n Brian Gottfried | 6–3, 5–7, 17–15 |
| Winner | 3. | 1974 | Houston, US | Clay | Rod Laver | Arthur Ashe\n Roscoe Tanner | 4–6, 7–6, 6–4 |
| Runner-up | 7. | 1975 | Orlando WCT, US | Hard | Ray Ruffels | Brian Gottfried\n Raúl Ramírez | 4–6, 4–6 |
| Winner | 4. | 1975 | St. Louis, US | Clay | Ray Ruffels | Ross Case\n Geoff Masters | 6–4, 6–4 |
| Winner | 5. | 1975 | Istanbul, Turkey | Outdoor | Thomaz Koch | Colin Dowdeswell\n John Feaver | 6–2, 6–2, 6–2 |
| Winner | 6. | 1976 | Palm Springs, US | Hard | Sandy Mayer | Raymond Moore\n Erik Van Dillen | 6–4, 6–7, 7–6 |
| Winner | 7. | 1976 | Palma, Spain | Clay | John Andrews | Mark Edmondson\n John Marks | 2–6, 6–3, 6–2 |
| Runner-up | 8. | 1976 | Madrid, Spain | Clay | John Andrews | Carlos Kirmayr\n Eduardo Mandarino | 6–7, 6–4, 6–8 |
| Winner | 8. | 1976 | Florence, Italy | Clay | Carlos Kirmayr | Péter Szőke\n Balázs Taróczy | 5–7, 7–5, 7–5 |
| Winner | 9. | 1977 | Little Rock, US | Carpet | Haroon Rahim | Bob Hewitt\n Frew McMillan | 6–7, 6–3, 6–3 |
| Winner | 10. | 1977 | Denver, US | Carpet | Geoff Masters | Syd Ball\n Kim Warwick | 6–2, 6–3 |
| Winner | 11. | 1977 | South Orange, US | Hard | Wojtek Fibak | Ion Ţiriac\n Guillermo Vilas | 6–1, 7–5 |
| Runner-up | 9. | 1977 | Tokyo Outdoor, Japan | Clay | Chris Kachel | Geoff Masters\n Kim Warwick | 2–6, 6–7 |
| Winner | 12. | 1978 | Little Rock, US | Carpet | Geoff Masters | Tim Gullikson\n Tom Gullikson | 7–6, 6–3 |
| Runner-up | 10. | 1978 | Johannesburg, South Africa | Hard | Geoff Masters | Bob Hewitt\n Frew McMillan | 5–7, 6–7 |
| Runner-up | 11. | 1978 | Newport, US | Grass | Bob Giltinan | Tim Gullikson\n Tom Gullikson | 4–6, 4–6 |
| Winner | 13. | 1978 | Columbus, US | Clay | Bob Giltinan | Marcello Lara\n Eliot Teltscher | 6–2, 6–3 |
| Runner-up | 12. | 1979 | San Jose, Costa Rica | Hard | Anand Amritraj | Ion Ţiriac\n Guillermo Vilas | 4–6, 6–2, 4–6 |
| Runner-up | 13. | 1979 | Tulsa, US | Hard (i) | Tom Gullikson | Francisco González\n Eliot Teltscher | 7–6, 5–7, 3–6 |
| Runner-up | 14. | 1979 | Stowe, US | Hard | Anand Amritraj | Mike Cahill\n Steve Krulevitz | 6–3, 3–6, 4–6 |
| Runner-up | 15. | 1979 | Tel Aviv, Israel | Hard | Mike Cahill | Ilie Năstase\n Tom Okker | 5–7, 4–6 |
| Winner | 14. | 1979 | Tokyo Outdoor, Japan | Clay | Pat Du Pré | Rod Frawley\n Francisco González | 3–6, 6–1, 6–1 |
| Winner | 15. | 1979 | Adelaide, Australia | Grass | Chris Kachel | John Alexander\n Phil Dent | 6–7, 7–6, 6–4 |
| Winner | 16. | 1980 | Metz, France | Carpet | Gene Mayer | Chris Delaney\n Kim Warwick | 7–6, 7–5 |
| Winner | 17. | 1981 | Adelaide, Australia | Grass | John James | Craig Edwards\n Eddie Edwards | 6–3, 6–4 |
Question:
which surface has the most winners?
Answer:
Hard