I've watched this fight three times now, but even watching it live, it was clear to me that Conor McGregor was carried by Mayweather. I'll explain in light detail as to why it was clear:
1. In the first three rounds, Mayweather threw a total of 28 punches, compared to McGregor's 115. Mayweather landed 12 of those shots (43%). McGregor landed 26 (23%). These are the three rounds that most fans give to McGregor, simply for the lack of activity from Mayweather. However, over the course of the last seven rounds, the numbers are much different. After the first three rounds, Mayweather averaged 33 punches per round, landing a ridiculous 67% of them. For comparison, McGregor threw 45 punches per round, but landed only 26% of them. The numbers are quite clear: Once Mayweather started punching, he hit McGregor at will, while McGregor was missing 3/4 punches, and even less of his power punches. Once Mayweather started punching, the fight wasn't even close.
2. Mayweather did this while fighting uncharacteristically. Mayweather completely ditched his hyper-defensive style. His footwork was largely flat. His shell defense was gone. Even his head movement was lacking in the speed and precision boxing fans are accustomed to. Mayweather often lunged into punches instead of staying square above his hips. McGregor's best chance at winning the fight was always going to be a counter left, and Mayweather handed the opportunities to him in spades. McGregor could not capitalize on Mayweather's uncharacteristically sloppy fighting. I've seen people blame it on Mayweather's age, but these aren't age-related techniques that he was missing. If he was a step slower than we thought he'd be, that would be one thing, but his signature style that brought him 49 consecutive wins was mysteriously gone. The only explanation to him abandoning his style was that he wanted, in his own words, to "give the fans a good fight". It wouldn't be a good fight if Mayweather had gone out and countered McGregor flawlessly and knocking him out in 4 rounds. It was a "good fight" because it made Conor "look good".
3. Mayweather let Conor escape constantly. Mayweather is notoriously good at cutting off the ring against opponents when he's moving forward. Against Conor, he gave up distance and allowed Conor to move laterally in circles, almost as though they were fighting in an octagon instead of a ring. Perhaps a gentleman's agreement? Mayweather's best counters come when he traps an opponent in a corner and counters desperate shots; Against McGregor, he never even attempted to get in McGregor's path to pursue one of his trademark skills.
I don't know if Conor has giant balls, or loves money more than brain cells, and I've certainly been hard on him before and after the fight. Mad respect for even climbing in the ring against one of the greatest of all time; That said, it is clear even on a very basic analysis of the fight that Mayweather didn't take it seriously, and allowed Connor to look "good" to the uninitiated. It was a fun fight, but it wasn't competitive.
I believe that Mayweather abandoned the skills that he was best at to allow McGregor to look competitive. He did it for the fans after promising to make up for the Pacquiao fight. That said: I think Mayweather could have finished the fight much earlier if he treated McGregor like a real boxer.
just a friendly suggestion something more pleasant and less disgusting maybe. 
