Strange things boxing taught you?

What i don't understand is this.If Froch-Groves can do 80,000+ then why do the big fights over the pond take place in 16,000-20,000 arenas. In a lot of cases, casinos pay for the fights, and the majority of them don't have capacity beyond 20,000. Saul Alvarez did 40,000 in San Antonio Alamodome.

The bigger they are. The better they are. If you're HW champion of the world, you're the best and most dominant boxer in the world and beat any other boxer across all weight classes. There is no such thing as "P4P" P4P lists are people's way of dealing with little man syndrome

No one is immune from an ass whooping, i.e. The Fan Man......

What i don't understand is this.If Froch-Groves can do 80,000+ then why do the big fights over the pond take place in 16,000-20,000 arenas.