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Phil Mickelson has turned back the clock at Kiawah Island, entering the third round of the 2021 PGA Championship tied for the lead. With a victory at the PGA Championship 2021, Mickelson will become the oldest major winner (50) in golf history. Mickelson fired a three-under 69 on Friday, thanks to five birdies on his final nine holes. The 50-year-old is joined by Louis Oosthuizen atop the 2021 PGA Championship leaderboard at five-under par. 

Meanwhile, Brooks Koepka, who won this event in 2018 and 2019, is one shot off the lead, and he's being listed as the 4-1 favorite at William Hill Sportsbook. Mickelson is being listed at 12-1, while Oosthuizen is going off at 11-2 in the latest 2021 PGA Championship odds. With so many experienced players atop the leaderboard, you'll want to check out the PGA Tour predictions from the proven computer model at SportsLine before locking in your 2021 PGA Championship picks.

SportsLine's prediction model, built by DFS pro Mike McClure, has been on fire since the return of the PGA Tour in June. In fact, it's up nearly $10,000 on its best bets since the restart, nailing tournament after tournament.

At the 2021 Masters, McClure nailed Jon Rahm's (+250) top-five finish, as well as Corey Conners' (+550) top-10 showing. All told, McClure's best bets netted over $450 at the Masters.

In addition, McClure was all over Daniel Berger's win at +1400 in his best bets at the AT&T Pebble Beach Pro-Am in February. McClure also nailed Viktor Hovland's (+2500) victory in the Mayakoba Golf Classic in December. That was one of many huge calls he's made in the past few months.

This same model has also nailed a whopping six majors entering the weekend. Anyone who has followed its golf picks has seen massive returns.

Now that the 2021 PGA Championship cut has been made, SportsLine simulated the final two rounds 10,000 times, and the results were surprising. Head to SportsLine now to see the projected 2021 PGA Championship leaderboard.

The model's top 2021 PGA Championship predictions 

One huge shocker the model is calling for: Mickelson, a five-time major champion and one of the top Vegas favorites, stumbles and fails to crack the top five. The 44-time PGA Tour champion has won five major championships in his career, and he can become the 14th golfer in history to win six or more majors this weekend at the Ocean Course on Kiawah Island.

However, Mickelson entered the 2021 PGA Championship ranked 199th in driving accuracy percentage (50.99), and with the forecast calling for more windy conditions over the weekend, that could spell trouble for the 2005 PGA Champion. If Mickelson is unable to find the fairway off the tee in the final two rounds, he'll be in major trouble given the tough course conditions at Kiawah Island. 

Another surprise: Paul Casey, a 20-1 long shot, makes a strong run at the title. Casey has consistently shown he can play with the best players on tour and he enters the weekend in a tie for seventh, just three shots off the lead. 

Casey has racked up seven birdies through the first two rounds and he's been able to limit the damage when he's found himself in trouble. The Englishman entered the 2021 PGA Championship ranked inside the top-20 in strokes gained: tee-to-green (1.100) and strokes gained: approach the green (.705), both of which will come in handy this weekend. Casey has 19 worldwide victories in his career, and SportsLine's model expects he'll make a strong run at the Wanamaker Trophy. 

How to make 2021 PGA Championship picks

The model is targeting three other golfers with PGA Championship 2021 odds higher than 20-1 who will make a surprising run, including an epic underdog. Anyone who backs these underdogs could hit it big. You can only see them here.

So who will win the 2021 PGA Championship? And which long shots stun the golfing world? Check out the odds below and then visit SportsLine to see the projected 2021 PGA Championship leaderboard, all from the model that's nailed six golf majors and is up nearly $10,000 since the restart.

2021 PGA Championship odds

Brooks Koepka 4-1
Louis Oosthuizen 11-2
Hideki Matsuyama 15-2
Bryson DeChambeau 12-1
Phil Mickelson 12-1
Corey Conners 20-1
Branden Grace 20-1
Christiaan Bezuidenhout 20-1
Paul Casey 20-1
Sung-Jae Im 25-1
Gary Woodland 25-1
Viktor Hovland 25-1
Joaquin Niemann 28-1
Matthew Fitzpatrick 40-1
Kevin Streelman 45-1
Shane Lowry 50-1
Collin Morikawa 50-1
Rory McIlroy 50-1
Jason Kokrak 60-1
Cameron Smith 66-1
Will Zalatoris 80-1
Jon Rahm 80-1
Martin Laird 80-1
Keegan Bradley 80-1
Charley Hoffman 80-1
Tony Finau 125-1
Jordan Spieth 125-1
Bubba Watson 125-1
Ian Poulter 125-1
Abraham Ancer 125-1
Patrick Cantlay 125-1
Lee Westwood 125-1
Padraig Harrington 125-1
Harry Higgs 150-1
Richy Werenski 150-1
Tyrrell Hatton 150-1
Scottie Scheffler 150-1
Matt Wallace 150-1
Tom Lewis 200-1
Justin Rose 250-1
Daniel Berger 300-1
Rickie Fowler 300-1
Carlos Ortiz 300-1
Matt Jones 400-1
Cameron Davis 400-1
Garrick Higgo 400-1
Aaron Wise 500-1
Jason Scrivener 500-1
Russell Henley 500-1
Talor Gooch 500-1
Harold Varner 500-1
Stewart Cink 500-1
Denny McCarthy 500-1
Sam Horsfield 500-1
Webb Simpson 500-1
Daniel van Tonder 500-1
Robert Macintyre 500-1
Rasmus Hojgaard 750-1
Steve Stricker 750-1
Jimmy Walker 750-1
Patrick Reed 1000-1
Joel Dahmen 1000-1
Byeong Hun An 1000-1
Harris English 1000-1
Alex Noren 1000-1
Billy Horschel 1000-1
Dean Burmester 1000-1
Tom Hoge 1000-1
Lucas Herbert 1000-1
Ben Cook 2000-1
Jason Day 2000-1
Danny Willett 2000-1
Adam Hadwin 2000-1
Brian Gay 2000-1
Brad Marek 2000-1