Penn is a former UFC welterweight and lightweight champion while Nick Diaz was the Strikeforce welterweight champion prior to leaving the organization for greener pastures.

Penn (16-7-2) comes into this three-round contest as the favorite over Diaz (26-7-1), as Penn has odds of -125 to top Diaz, who has a money line of -105. Both fighters have similar styles as each relies on boxing and jiu-jitsu to win fights. Penn may have the edge in regards to wrestling, but Diaz will have a big size edge in terms of mass and reach. Both fighters will be sure to leave everything in the octagon, which makes this fight very interesting.

The co-main event also has a very competitive contest as heavyweights Cheick Kongo (26-6-2) and Matt Mitrione (5-0) face off with the winner emerging as a top-10 contender in the division.

Mitrione is the slight favorite, with a money line of -140 while Kongo has odds of +110 to win. Both fighters are primarily strikers, but Mitrione packs the harder punch and is more mobile while Kongo has a slightly better ground game. Mitrione will look to keep the fight standing and stick-and-move while Kongo will look to utilize leg kicks and takedowns to finish the fight with ground-and-pound.

For complete UFC 137 betting odds, check out the jump.

UFC 137 Betting Odds & Fight Card

Saturday, Oct. 29, 2011

Mandalay Bay Events Center, Las Vegas, NV

Welterweight Bout -Nick Diaz (-105) vs. BJ Penn (-125)

Heavyweight Bout- Cheick Kongo (+110) vs. Matt Mitrione (-140)

Heavyweight Bout- Mirko CroCop (+220) vs. Roy Nelson (-280)

Featherweight Bout – George Roop (+265) vs. Hatsu Hioki (-325)

Lightweight Bout – Dennis Siver (+190) vs. Donald Cerrone (-240)

Featherweight Bout – Bart Palaszewski (+240) vs. Tyson Griffin (-300)

Bantamweight Bout- Jeff Curran (+300) vs. Scott Jorgensen (-400)

Light Heavyweight Bout – Brandon Vera (-500) vs. Eliot Marshall (+350)

Lightweight Bout – Danny Downes (+170) vs. Ramsey Nijem (-210)

Middleweight Bout – Francis Carmont (+100) vs. Chris Camozzi (-130)

Middleweight Bout – Clifford Starks (+100) vs. Dustin Jacoby (-130)

The WEC returns to action tonight on Versus at 9PM ET with WEC 51: Aldo vs. Gamburyan. The card is stacked and is a tremendous lineup given the fact this will be on free television. The main event features a title fight in the featherweight division featuring one of the top pound-for-pound fighters in the world. Here are my picks for the winner’s in tonight’s card.

WEC Featherweight Championship – Champion Jose Aldo (17-1) vs. Manny Gamburyan (13-5): Aldo is on a tear right now as he is coming off his dominant win over Urijah Faber at WEC 48. He has tremendous explosiveness with his kicks and punches while also being a jiu-jitsu black belt. Gamburyan is a force UFC lightweight competitor, but has found his home in the 145-pound division of the WEC. Manny is coming off a KO win over Mike Thomas Brown and his style could pose a problem for Aldo as he is short and compact with good wrestling and power in his hands. I think Gamburyan will make a fight of things, but ultimately Aldo will slowly break him down with leg kicks before landing a big punch in the third round to get the TKO win.

WEC Lightweight Bout – Jamie Varner (16-3-3, 2NC) vs. Donald Cerrone (11-3, 1NC): Both men are looking to get another shot at the lightweight title as each were submitted by champion Ben Henderson in recent fights. This is a rematch as well from a controversial decision in January of 2009. These two have bad blood and want at each other badly. Varner brings good boxing to the cage while Cerrone is more of a grappler and submission fighter. I look for Cerrone to keep Varner at distance with his length and then close inside and grapple his way to a decision victory.

WEC Bantamweight Bout – Miguel Torres (36-3) vs. Charlie Valencia (12-5): Torres has lost his last two bouts after being one of the top fighters in the world just about a year ago. In his last loss to Joseph Benavidez, Torres looked tentative and didn’t seem himself. Torres needs to come out with more reckless abandon in this fight like he has in the past because Valencia is a tough opponent that can push anyone to the limit. If Torres is to the top of his game, which I feel he will be, I see him winning by submission in the third round.

WEC Bantamweight Bout – Chan Sung Jung (10-2) vs. George Roop (10-7-1): Jung made a lot of fans with his war against Leonard Garcia at WEC 48 and in this fight, he faces a lesser opponent in George Roop. Jung can take a punch and he always pushes forward so I expect him to overwhelm Roop and earn a TKO victory in the first round.

WEC Bantamweight Bout – Leonard Garcia (18-5-1) vs. Mark Hominick (18-8): This match features two great strikers, but the difference in the fight will be Hominick’s technical superiority. Garcia tends to throw wild punches that leave him open to counter strikes. Look for Hominick to capitalize on one of those counters and dropping Garcia before taking his back and sinking in a choke in round three.