The Dolphins had a easy schedule in 1972. Only 5 of their 14 games involved opponents who ended up winning more games than they lost (against other teams), and those opponents' records were hardly impressive: 8-5, 7-6, 7-5, 8-5. Miami faced only one non-division opponent that year (Kansas City) who finished higher than third in their own division. They played the Oilers(1-13) once and Patriots (3-11) twice. They did beat the good teams to get to and win the SB but I think the undefeated season is overrated.