The outcome of the third fight isn't a matter of belief or opinion -- Frazier quit on his stool after the 14th round from exhaustion, and Ali was battering him at will at the time of the stoppage. As I mentioned earlier, probably the best heavyweight championship fight ever.
The second fight was a very boring affair with Ali winning easily on points -- no controversy. Frazier had a particularly bad outing -- he just wasn't on his game.
Frazier beat Ali only in the first fight, and that was a very close contest.
I was rooting like crazy for Frazier to knock Ali's head off in all three contests, but alas it just wasn't to be. The best moments Frazier had against Ali were the famous knockdown (left hook) in the 15th round of the first fight and the middle round (7th through 12th) pounding he administered the third fight.
I shouldn't have said he quit, but he was a clearly beaten man. All the snap to his punches was gone, and his defense was non-existent. His trainer Eddie Futch did the right thing.
What's interesting is that while this was going on in Frazier's corner, Ali was pleading with his own trainer (Angelo Dundee) to stop the fight because he was exhausted. Dundee refused, and Ali then told him that he would refuse to come out of his corner for the 15th if Dundee didn't stop it. But Frazier's corner quit first, and Ali was therefore declared the winner. An incredible episode.
If it went to the scorecards after 14 rounds, I'd probably have scored the fight even.