In very limited circumstances. If somebody went Last Boyscout, obviously that's a criminal charge. If somebody charged the mound and repeatedly hit another player in the head with a bat, I'd charge that.
Basically, it would have to be wanton disregard for the safety of others.
I was SO waiting for you to chime in, Roy :-)
So, I'll admit I'm an infrequent poster, but I'm also a criminal defense attorney, and I'll echo Roy's comments. It would, I think, LITERALLY take a scene out of "The Last Boy Scout" before I'd support criminal charges. Suspensions, banning from the league, fine. But criminal charges? No freaking way.
Here's the two major problems with arguments like yours, rutzan:
1.) All you focus on is the big issues, the McSorleys and Bertuzzis and Kermit Washingtons. But you can't be subjective; you either need to criminalize EVERY act that would, by the criminal code, be a crime or you need to criminalize NO acts. Under Massachusetts law, the clear-path foul that Paul Pierce executed on Andre Iguodala in Game 5 is, at the very least, an assault. If you take the kind of hockey play that you see probably 20 times a night during the NHL season -- guy slides to block a slapshot by an opposing player, takes the puck in the face, needs a stitch to close his lip -- in Wisconsin (where I practice), that's not only substantial battery -- a class I felony subject to a fine of not more than $10,000 and incarceration in the Wisconsin State Prison System for not more than 3 1/2 years -- but the fact that it was a slapshot qould qualify under the "dangerous weapon" penalty enhancer for an additional 4 years of prison time. You can call it flippant and exaggerated all you want, but you can't pick and choose the prosecution of those offenses. After all, the best way for evil to succeed is for good men to do nothing, right? :-)
2.) So let's say you say, "Fine! Prosecute all of them!" Who gets jurisdiction? Let's take the Pierce foul in Game 5 as an example. The gut reaction would be the county in which the game takes place (so, as it was at the Garden, it would be Suffolk County in Massachusetts). Then again, the Celtics are pretty well-loved in Suffolk County, and Pierce is a beloved Celtic, so the prosecution can't find an impartial jury of 12 people. So now we change venue to another county, but where do you find a group of 12 jurors in Massachusetts who aren't going to be predisposed to take Pierce's side by sheer virtue of sports idolatry? Do you move it to another state it didn't even take place in? The state courts don't have the authority to cross state lines just to get a jury. But wait! The NBA does business across state lines, so maybe it should be in federal court if you introduce box scores from other games across the country showing that Pierce has fouled other players before in other games, thus establishing a clear pattern of behavior for which the US Attorney's office has jurisdiction. See what I'm saying?
I'm not being tongue-in-cheek here. There's a reason these cases aren't prosecuted in criminal courts in the U.S. You can get as p---ed as you want about thug-like behavior in the pro leagues, but you can't selectively prosecute players for their actions, even if some are worse than others.