It's been said that you have to be good to be lucky and lucky to be good. Anderson Silva is living, breathing proof.

There's no question, of course, that the UFC Middleweight Champion is as great a mixed martial artist as the UFC has ever seen, and he showed that on Saturday night at UFC 148 when he successfully defended his UFC middleweight championship against Chael Sonnen. In that same fight, however, "The Spider" was also extremely lucky.

While there were initially questions surrounding the knee that Silva drove into Sonnen's chest in the second round - the move that eventually brought about the end of the fight - and whether it was actually an illegal knee to the head of a downed opponent, the biggest question involves the way in which Sonnen was "downed."

What on Earth could have possibly possessed Sonnen to attempt a spinning backfist against Silva?

The obvious answer, of course, was the fact that a minute into the second round, Sonnen was finding it much harder to take down the champion than he initially did in his dominant first round. Silva showed much better takedown defense in Las Vegas on Saturday than he did two years ago at UFC 117, and Sonnen felt the need to do something to put Silva back on the ground.

The something he chose, however, was hardly an inspired choice.

It must be said that one of the keys to Sonnen's success against Silva for four and a half rounds two years ago in Oakland was his willingness to engage Silva on the feet, not to mention his surprising success in doing so. While Sonnen's wrestling was the most important factor, he made Silva show some respect for his striking that made takedowns easier to set up.

There's a difference, however, between excellent use of some fairly basic striking techniques and an excessively fancy move thrown wildly. The former was a part of how Sonnen pushed Silva to his limit two years ago. The latter is how he opened the door for his own demise two days ago.

Silva deserves a great deal of credit for the way he was able to frustrate Sonnen with his takedown defense, of course - and there's no questioning his greatness as a champion - but it's safe to say that "the Spider" could never have imagined being handed an opportunity like the one Sonnen gave him with that spinning backfist attempt.

At this point, it's fairly safe to say that Sonnen is done with the middleweight title picture until Silva retires. One should never say never in this business, of course, but nothing that happened in Silva-Sonnen II did anything to suggest there might be a third installment. In the meantime, Sonnen will certainly have his share of enticing fights, ranging from other angry Brazilians who will want their pound of flesh from the trash-talking "Gangster from America" (Wanderlei Silva and Vitor Belfort come to mind) to up-and-comers looking to put themselves in position for a shot at the title.

While Sonnen has undoubtedly made himself quite a bit of money by being a foil for Silva - and helped Silva's career tremendously in the process - he said it himself during the buildup to the fight: you can only retire from a sport once you've won a world championship. Otherwise, you're just quitting.

Until he quits - or retires - Sonnen will have to ask himself what might have been.