Regular season
| Year | Team | Games | Att | Cmp | Cmp% | Pass Yds | Pass TD | INT | Sacks | Y/A | Rating |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1969 | DAL | 6 | 47 | 23 | 48.9 | 421 | 1 | 2 | 12 | 9.0 | 69.5 |
| 1970 | DAL | 8 | 82 | 44 | 53.7 | 542 | 2 | 8 | 19 | 6.6 | 42.9 |
| 1971 | DAL | 13 | 211 | 126 | 59.7 | 1882 | 15 | 4 | 23 | 8.9 | 104.8 |
| 1972 | DAL | 4 | 20 | 9 | 45.0 | 98 | 0 | 2 | 8 | 4.9 | 20.4 |
| 1973 | DAL | 14 | 286 | 179 | 62.6 | 2428 | 23 | 15 | 43 | 8.5 | 94.6 |
| 1974 | DAL | 14 | 360 | 190 | 52.8 | 2552 | 11 | 15 | 45 | 7.1 | 68.4 |
| 1975 | DAL | 13 | 348 | 198 | 56.9 | 2666 | 17 | 16 | 36 | 7.7 | 78.5 |
| 1976 | DAL | 14 | 369 | 208 | 56.4 | 2715 | 14 | 11 | 29 | 7.4 | 79.9 |
| 1977 | DAL | 14 | 361 | 210 | 58.2 | 2620 | 18 | 9 | 30 | 7.3 | 87.0 |
| 1978 | DAL | 15 | 413 | 231 | 55.9 | 3190 | 25 | 16 | 32 | 7.7 | 84.9 |
| 1979 | DAL | 16 | 461 | 267 | 57.9 | 3586 | 27 | 11 | 36 | 7.8 | 92.3 |