By concentrating hell lot of raiton chakra into my hand in order to apply a ton of pressurizing shape-manipulation in order to compress it's mass of lightning energy into a ball I make...
More raiton make it grow larger, at least the size of a basket ball. But remember you're pressuring a lot of raiton chakra into that ball. Therefore, you need precise and flawless chakra control or the ball will Ka-pow on your hand. Try to explain me how does the ball feel on your hand, does it crackle loudly?