It is hard for me to even think McGregor has a puncher's chance. The idea that he can land a solid enough punch to cause a knockout seems ridiculously unlikely to me.
It takes years to develop the footwork to even put a fighter in position to land a solid punch on a guy like Mayweather. You can count on one hand how many times Floyd has been caught, and that is by professional boxers, which McGregor is by definition not.
I expect you will hear the crowd ooh and ahh alot when Floyd is "trapped in the corner" (he isn't actually trapped but he's letting his opponent think he is, see Ricky Hatton), because McGregor will be throwing 3 punches a second and look like he's onto something, when in reality they will show slo-mo in between rounds and it will be clear that he actually landed 0/120 shots.
I will probably watch because 1. I am a big boxing fan and appreciate Floyd's mastery of the shell and counterpunching, and 2. this would be upset of the century level if somehow McGregor pulled it off. I am just expected to be pretty disappointed in the competition level.