Tennis, badminton, handball, volleyball and ping-pong are all clearly related.
Ditto on basketball, soccer, football, polo, water polo.
Ditto cricket and baseball.
Please note, of course, that these sports, or sports very much like them, have occurred independently in cultures widely separated from one another, sometimes with no chance of contact.
Is it because they follow simple and basic concepts of competition? Are polo-like games all physical expressions of "assert control over your own area while expanding into the enemy area" as is what's found in war? Are tennis-like games all the "pass the burden of action onto the enemy, if possible in such a way that they will become unable to act" which we find in debate? Does baseball have any point whatsoever?
These are not conjectures or mysterious questions. I consulted the cockle shells, and the diachronic sportologists, and the political masterminds, and finally got my answers. They'll kill me for this, and shut down LiveJournal too, I'm sure, but my hope is you'll see this before they notice.
The basic principles which lie behind these sports are, in fact, beamed by laser from outer space. But they aren't based on the competitive urges for war and debate. It's the other way around. We war because we play basketball. We argue because we play tennis.
And, um, I have no idea what baseball is all about.