UFC 137 Predictions: B.J. Penn Will Outlast Nick Diaz in Unanimous Decision

Perhaps no UFC card has undergone more intense changes than Saturday's UFC 137, but the card is officially set with B.J. Penn taking on Nick Diaz in a welterweight bout in the main event of the night.

The main event was initially slated to be Diaz against Georges St-Pierre, but Diaz was removed from the fight for failing to make media appearances and St-Pierre was removed from the card all together due to a knee injury.

This left UFC with little choice but to pit the 16-7-2 Penn and the 25-7-1 Diaz against each other. The bout should certainly be a very competitive one, as both fighters are very evenly matched. Diaz would seem to have the momentum going in with 10 straight victories, but none have been over a fighter the caliber of Penn.

Penn fought Jon Fitch to a draw in his most recent match, and defeated Matt Hughes prior to that. His win over Hughes came on the heels of back-to-back unanimous decision losses to Frankie Edgar in 2010. Saturday will mark Penn's first fight since February, so rust could be a factor.

In looking at the career records of both fighters and the manner in which each of them competes, I find it very likely that this match is going to go to the scorecards. Penn has been knocked out just twice during his career and has never submitted, while the exact same is true of Diaz.

Both men have good chins and are unlikely to tap out, so I most certainly see the judges deciding this one. Of Diaz's last 10 wins, only one of them was by decision, that being his unanimous victory over Karl James Noons in a Strikeforce bout in October of last year.

Penn hasn't won by decision since 2005 when he defeated Rodrigo Gracie. With all of that said, something most definitely has to give. Both fighters can strike with the best of them, but they are very methodical as well and won't easily be put in unfavorable positions.

Each fighter is equally capable of winning, but I think Penn's big-fight experience will give him the edge. Diaz has certainly been in some important fights, but he doesn't compare to Penn in that regard. I like Penn to come out with a unanimous decision in what I expect to be a fairly cautious bout.