That'd probably be the best way to do it. If I was in possession of infinity-billion dollars tho I'd figure out a more complex system wherein players wear high-tech suits like those prototype gladiator ones that can determine death dealing blows but keep the man inside safe of any real damage. The ball would have to have some kind of electro magnet thingy so it'd stick to your hand when you pick it up (also activating flashing orange lights on your armour.) and then fall out of your hand when you get hit hard enough. ...I suppose your suit would have to shut down or something so you couldn't move anymore...... Someone should actually put some thought, and science, into this idea. Or we could just play Football.

No. When hit with gravity hammers, most humans would be unable to walk anywhere