there's no such thing as playing basket unless you want to imply that there is which is fantasy and in that case, you'd be right, and there could be a ball playing basket. Playing basket would be whatever your imagination states that to be I guess =/

If you say "I saw a dog-eating chicken" then you're implying you saw a chicken that can eat a dog unless you say "I saw a dog eating chicken" which you're then implying you saw a dog which was eating chicken.

It's all in the grammar man.

So if you said "I saw a ball playing basket" the you're implying you saw a ball playing basket, whatever you want playing basket to mean.

If you say "I saw a ball-playing basket" then you're implying you saw a basket which can play ball.

If you're writing a story about a magic basket that has the ability to play a game called "ball" in a fantasy world, that would be plausible and make perfect sense.

You dig me?