Errol Spence Jr. explains why he wants to the best pound-for-pound undisputed welterweight in the world and what he expects from fighting Shawn Porter. (1:04)

At this point, it's the only question worth asking: Who will win Saturday night's welterweight unification title bout between IBF titleholder Errol Spence Jr. and WBC titlist Shawn Porter at Staples Center in Los Angeles?

Spence (25-0, 21 KOs) is coming off a dominant unanimous decision victory over Mikey Garcia in March. Porter (30-2-1, 17 KOs) defeated Yordenis Ugas by split decision also in March.

Who takes the win? Our experts make their picks.

Dan Rafael

ESPN.com

Spence by decision

I love this fight and expect it to be somewhat competitive, but Spence is a pound-for-pound caliber talent with no real flaws in his game. I just think he does everything at least a little better than Porter. In the end that will show through with Spence winning by a competitive but clear decision.

Mark Kriegel

ESPN boxing analyst

Spence by late TKO

Porter's great talent is his engine, a relentless will to pressure and maul. It's difficult not to admire him. But it's just as difficult to see how he wins here. Spence has the advantage in height, reach and power. Porter's not beating him from distance; his only shot is coming in. That's where he gets caught -- with Spence's exceptional jab, and perhaps a lead hook. Then there's that hook to the body. Spence does it as well as anyone, certainly well enough to make even Porter a little less relentless. Question is whether Spence stops him. I think it's more than likely he does late, in the 11th or 12th.

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Nick Parkinson

ESPN UK

Spence by decision

It might be messy early on as Porter tries to turn it into a dog fight, but Spence's reach and boxing skills should see him pull away for a comfortable points win. Spence is in good and improving form. It's hard to go against him.

Teddy Atlas

ESPN boxing analyst

Spence by decision

Porter showed a different look in the Yordenis Ugas fight. Rather than fire and brimstone, he sprinkled in some jabs and footwork. Not sure if it was a dress rehearsal for the Spence fight, but in the end, whether coming forward or moving around, there is no area inside the ring where Porter can outperform Spence. Spence drops Porter with a counter shot, on his way to a one-sided decision.

Nigel Collins

ESPN.com

Spence by unanimous decision

Porter abandoned his usual roughhouse style in his most recent fight, and although he won a 12-round split decision over Ugas, his performance was not impressive. He's not going to outbox Spence, so reverting to his swarming style would probably be Porter's best bet. If he does, it will result in a more entertaining fight, but it won't be enough to beat Spence, a multitalented fighter in his prime.

Steve Kim

ESPN.com

Spence by decision

Spence has all the advantages, physically and fundamentally, and while Porter is certainly a hard-nosed and rugged grinder, I just don't see him having the offensive firepower to match Spence's. In addition to being the better pure puncher of the two, he is also the smoother boxer from the outside.

Eric Raskin

Showtime Boxing

Spence by decision

I hope Porter isn't planning to box in this fight, a strategy that cost him rounds in his past couple of fights and won't serve him well against Spence. If Porter is the best version of his awkward pressure fighter self, he can give Spence some problems. Either way, I favor the longer, slicker, more technically precise Spence over the distance.

Joe Cortez

ESPN Deportes

Porter by split decision

Porter has a lot more experience against top fighters and that will help him against Spence. Close fight, but I think Porter will take a split-decision victory.

Charles Moynihan

ESPN bureau producer

Spence by TKO

If he isn't the face of boxing right now, Spence may very well be the No. 1 pound-for-pound fighter in a year. Power, hand speed and footwork is the difference in this fight. Porter is a plodder -- always comes straight ahead with no lateral movement and changes angles and levels infrequently. Porter receives his final big payday and his ledger receives an L in the process. Spence victorious via 11th-round TKO.

Salvador Rodriguez

ESPNdeportes.com

Spence by decision

This could be the most difficult fight Spence has had in his career, because that is precisely Porter's specialty: making fights difficult for anyone. In the end, Spence is going to be OK. Spence will impose his best technique and speed on a warrior like Porter to take a unanimous-decision victory.

Claudia Trejos

Boxing analyst

Spence by decision

The fighters' style should allow this to be a good fight. Porter, being a short 147, is giving a big advantage on size to Spence. While Porter has shown skills and grit, Spence is a taller, longer and a better boxer. I believe Spence will systematically break down the veteran to take the win by decision.

Bernardo Pilatti

Boxing analyst

Spence by unanimous decision

Helped by his experience, Porter will complicate Spence's fight plan in the first three or four rounds. After that, the IBF champion will control the battle with his power and size to win a decision in all the cards.

Jorge Eduardo Sánchez

ESPN Deportes boxing host

Spence by decision

Porter has an awkward style, nobody looks good against him. He has the ability to complicate his opponent's strategy. He moves well and slips most shots under his opponent's guard. However, Spence is on another level. He's bigger and attacks the body very well. Spence is superior, he has better skills and he will prove it.

play 1:31 Spence: Pacquiao is the biggest fight for me Errol Spence Jr. wants to face Manny Pacquiao next and not Terence Crawford after Shawn Porter, because facing Pacquiao would be a lucrative fight.

Manny Pacquiao

Welterweight titlist

Spence by decision

It's going to be a good fight, a close fight, but I think Spence will win. It's not gonna be a one-sided fight, it's gonna be a competitive fight. The fans will be treated to a once-in-a-lifetime experience in this fight.

Deontay Wilder

Heavyweight titlist

Spence by unanimous decision

Spence and Porter is a clash of styles that makes for an exciting, high-profile unification fight. Errol is trying to be ruler of the division with a statement win, so I expect him to come out and perform. Shawn is going to come for the full 12 rounds, no matter what. Errol has never fought anyone like that, which makes this so intriguing. But I see Errol as being the best in the division, hands down, and I'm picking him by unanimous decision. I don't see him knocking Shawn out.

Andy Ruiz Jr.

Unified heavyweight titlist

Porter by split decision

I've trained -- practically grown up -- with Porter, who has a difficult style. Spence is a great fighter and Shawn's the underdog, but I was the underdog against Anthony Joshua and we all know what happened there. Shawn's probably gonna have to be rough in there and stay on the inside, but I expect him to do it and win a decision.

Mikey Garcia

Former four-division titlist

Spence by decision

I don't believe Spence will win by a knockout. I believe that it goes 12 rounds, but I do have Spence beating Porter.

Keith Thurman

Former unified welterweight titlist

Spence by decision/late KO

This is two world-champion warriors going at it in a great fight. They have a common opponent in Kell Brook, who beat Porter and was knocked out by Spence. That's why my pick is Spence. Styles make fights, and Shawn's aggression could be difficult for Spence to handle since Spence has never faced an opponent like Shawn. Shawn is gonna come hungry but Brook and I handled that pressure, and I believe that Spence -- being a tall southpaw with power and a great jab -- will be able to deal with it as well. Spence has the power to stop Shawn, and if he does, I believe that would happen in the later rounds, like he did Brook.

Yordenis Ugas

Welterweight contender

Porter by decision

It is a great confrontation of two world champions. I think Spence is a favorite because of the great fighter he has proven to be. But Porter is a tough fighter with a great résumé and will fight hard until the final bell. I have no favorite in this 50-50 fight, but I lean toward Porter to win.

Robert Guerrero

Former two-time world titlist

Porter by split decision

This is a very difficult fight to call, but I've gotta go with Porter to beat Spence. With Spence being as tall as he is, Porter can't try to box like he did against Ugas, or Spence will pick him apart.

Paulie Malignaggi

Former three-time world titlist

Spence by late KO

Porter relies on a physical presence but Spence is a very big welterweight and that can nullify Porters' physicality. Spence's body punching is key.

Your take: