Some statistics on Missile effectiveness, from the book "Clashes: Air Combat over North Vietnam 1965-1972"
During Rolling Thunder:
AIM 7 (D & E) Sparrow Results (340 total): Hits 8% (27), Misses 29% (99), and Failures 63% (214).
AIM 9B Sidewinder Results (187 total): Hits 15% (29), Misses 28% (53), and Failures 56% (105).
AIM 9D Sidewinder Results (99 total): Hits 19% (18), Other 81% (81)
AIM 4D Falcon Results (44 total): Hits 9% (4), Other 91% (40)
During Linebacker :
AIM 7 (E2) Sparrow Results (281 total): Hits 12% (34), Misses 22%, and Failures 66%.
AIM 9J Sidewinder Results (31 total): Hits 13% (4), Misses 13% (4), and Failures 74% (23).
AIM 9G Sidewinder Results (50 total): Hits 46% (23), Other 54% (27)
Overall:
AIM 7 Sparrow Results (612 total): Hits 9% (56), Misses 25% (152), and Failures 66% (404).
AIM 9 Sidewinder Results (454 total): Hits 18% (81), Misses 35% (160), and Failures 47% (213).
Note: Take out the very late war success of the Navy's AIM-9G (46%) and the overall Sidewinder success rate is much lower.