hehe .. i think he knows somehow
i think when it began it was called PSt photoshop tennis, but as younger design culture took it up they changed the name to photoshop battles etc.
trying to give it a cooler approach, but i think tennis is fine.
It is a pretty funky game, nothing really teaches you how to get the most outta photoshop like having to manipulate whatever your given into something worthwhile.
If you want to increase your skills this is a great way to do it.