In Super Smash Bros. Brawl for the Wii, there are 41 total single player events. You start off with 1 through 10 and have to unlock the rest.
Events 11 to 20 – Complete seven events
Events 21 to 28 – Complete the Subspace Stage in Adventure Mode
Events 29 to 40 – Unlock all hidden characters
Event 41 – Complete the first 40 single player events