Adelaide boy here, but I hardly think calling Melbourne the sporting capital of the world is delusional.
The AFL grand final is held in Melbourne and is by far the biggest yearly sporting event in the country, and probably one of the biggest yearly domestic sporting events in the world.
Melbourne Cup, the most prestigious horse race in the world.
Australian Open, held in Melbourne.
Gramd Prix, Melbourne.
And any time an international team comes to play in any sport in Australia, where do they go? You guessed it, Melbourne.
Most states in the world have maybe 1 or 2 sporting claims to fame, Melbourne have at least four. And in the sports where they're not the number 1 spot in the country or world for, they also do it at least well, such as the cricket, soccer, and increasingly, the basketball.
I'd say Melbourne is the sporting capital of the world unless someone can show me a city that is any better.