so they can have one hand bigger than the other? or what for?

Ha ha, no, so they someday can pay for your retirement.

er, you know... so they can become high-paid tennis celebrity pros... go to Wimbledon... make lots of money in endorsements... give lots of money to dad and mum...

i just want one little boy named hamilton westford whatevermylastnameis. he'll be guaranteed to be at least 50% genetically awesome.

Genetics schemetics. He won't add up to squat without those tennis lessons.

nah, he's going to be a master of some total niche sport.