Besides, I had no idea before McEnroe spoke up that there are times when foot faults are illegal and other times when they’re not. I just thought they were bad all the time because that’s what the rules say. But McEnroe and others apparently feel the rules are overrated.

But that’s how he behaved when he was playing. The judges were always out to get him, and they used those pesky rules to do it.

That’s just wrong. The baseline judge is supposed to call foot faults. It’s in the job description. The rules don’t say that foot faults should be called only on meaningless points or only early in the match or only on the sixth Tuesday of the month. The rules say if you step on the line during your serve, it’s a fault.

I can understand how Williams would be shocked to have a foot fault called. I even understand how she would be upset to have it happen at that moment during a match that wasn’t going her way at all.

But that’s where understanding ends. I can see screaming in dismay and even protest, but not approaching the umpire with brandished racket and expressing a desire to shove a bleeping tennis ball down her bleeping throat.

Slideshow   Quips and quotables Take a look at what the players are saying at the U.S. Open. more photos

I can understand the desire to lay more than a $10,000 fine on Williams for what could be viewed as a physical threat. The judge apparently thought that the player threatened to kill her. That seems doubtful, though if Serena Williams advanced on me with veins bulging and racket waving, I’d check my life insurance, too.

The point is she didn’t hit the judge, didn’t appear to directly threaten the judge, and didn’t do anything other than have an old-fashioned McEnroe-style meltdown. As soon as she was disqualified, she calmed down and even congratulated Clijsters on her victory.

She didn’t carry her complaint into the interview room, didn’t continue to abuse the officials and the rules as she has done on occasion in the past. By all indications, Williams realized she went off the deep end and had no one to blame but herself.

She’s out of the tournament and a bit lighter in the wallet. It should be enough.

Also on NBCSports.com Posnanski: Emrick still rises above the rest What does retirement hold for Beckham? Oxbow ruins Orb's Triple Crown bid at Preakness Follow us on twitter: @NBCSports  |  Facebook