The 2021 PGA Championship starts this week with 156 golfers teeing it up on the Ocean Course at Kiawah Island. Not all of them have a shot of winning, of course, and as Brooks Koepka pointed out a few years ago, there are really only 30 guys he has to worry about.

There might be fewer this week as a bad side of the draw could spell trouble for the biggest stars in the game with winds whipping around Kiawah like they did in the second round of the 2012 PGA Championship when the scoring average ballooned.

Regardless, I have reduced Koepka's list to 21 names (well, technically 22), and coincidentally, he's not on it. With a gimp knee and just two rounds of play since the Masters, I'm unconvinced he's fit enough to go win his fifth major championship.

Using a combination of recent statistical trends, history at PGAs and what I've watched from players over the last few months, here's the most likely golfers to win this year's PGA Championship at Kiawah Island. Don't forget to take a look at our full set of PGA Championship odds, courtesy of William Hill Sportsbook.

1. Jordan Spieth (2nd in 2015): As has been stated pretty much everywhere you look, this is almost certainly Spieth's best look at the career grand slam since he finished T28 at the 2017 PGA Championship. He has been (double-checks notes) the best player in the world over the last three months if you're looking at advanced statistics, and it's not an overly hot putter that's carrying the day, either. Some of the tee and approach shots at Kiawah are truly terrifying, and as recently as two months ago, I would have side-eyed Spieth finding success here. However, after watching him drive it like a stallion at Augusta National, and considering how well he's working his irons, I'm way in on him contending for a fourth major championship this week.

2. Rory McIlroy (Won in 2012, 2014): It's an easy through line to draw with him winning here in 2012 as well as two weeks ago at the Wells Fargo Championship, but I'm not sure it's the correct one. Even when McIlroy has been at his best since 2014 when he last won a major championship -- and he has had some laugh-out-loud good years -- he has not often contended for majors (or at least not as often as his talent level suggests he should have). There seems to be a slight mental lapse at times at the biggest events, even if it's a tiny one. It's something to keep in mind, though maybe this return (his first return to a course where he won one of his four majors) will be what he needs to erase it for good.

3. Justin Thomas (Won in 2017): His ability to hit greens from pretty much everywhere should be even more beneficial than normal here, especially if it's windy. He's coming off a win at a different Pete Dye track (TPC Sawgrass), and if the driver cooperates -- if he's in play a lot -- he'll contend for Wanamaker trophy No. 2.

4. Bryson DeChambeau (T4 in 2020): Listen, if DeChambeau can win at Winged Foot, he can win anywhere in the world. The distance of this course should play into his hands, but some of the tight holes might not depending on how liberally he swings driver. He'll have to be smart around Kiawah -- he has proven he can be smart at major championship venues -- and really lean on a the well-rounded game he's shown off over the last six months.

5. Dustin Johnson (2nd in 2019): I'm trying to figure out what D.J. would have to do leading into a major to reduce my confidence in his ability to flip a switch and win that major. Certainly withdrawing from a PGA Tour event the week before and no top 10s in three months is not going to do it. We're talking about somebody who, after shooting a pair of 80s and withdrawing mid-tournament last summer, went on to nearly sweep the PGA, U.S. Open and Masters over the course of the next several months. D.J.'s iron play of late has not been up to his normal baseline, but like Rory McIlroy did back in 2012, I do wonder if he can lean on driver a bit more than usual and give himself a handful more wedges than mid or long irons. If so, that elusive PGA is in play.

6. Jon Rahm (T4 in 2018): The most consistent player in the world has wobbled a bit over the last few months. This is understandable, of course, given that Rahm and his wife had their first child just before the 2021 Masters, but his poor play led to a missed cut at the Wells Fargo Championship and a real lack of momentum coming into this tournament. There's a case to be made that Rahm is the best player in the history of the sport who does not have a major championship, and while I do not expect that to change this week, I wouldn't be surprised if it did given his propensity to stare down uncomfortable shots like players will face at Kiawah.

7. Collin Morikawa (Won in 2020): His stats over the last three months are difficult to comprehend. He's been a negative with the putter and a slight negative around the greens, and yet, he's sixth overall in strokes gained because he's gaining 2.7 in ball-striking. In other words, if he was just PGA Tour average with his short game, he would be having one of the great seasons of the last 20 years. That's why it's so easy to envision him popping up on leaderboards. When all you have to do is putt average -- not good or great, just average -- it's easy for us to talk ourselves into a motherlode of major championships.

8. Viktor Hovland (T33 in 2020): The only golfer in the world averaging at least 0.9 strokes gained in both driving and approach shots over the last six months. The short game holding up late could be a concern given that, you know, he's said it's a concern, but it's not difficult to envision him hitting the shots demanded by this course to get into contention. Can you imagine the Norwegian airwaves after what they did during his Mexico win last year?!

9. Will Zalatoris (n/a): He's been beaten by six golfers in two majors so far this season, which is nearly as remarkable as his ascent into the top 30 in the Official World Golf Rankings. Zalatoris' ball-striking is legitimately top-10-type stuff, and that's what will be needed if it heaves at Kiawah. He would become the 10th player to win in his PGA Championship debut but the second in the last 10 months (Morikawa was playing his first last August).

10. Daniel Berger (T12 in 2018): I absolutely love Berger coming into this week. He can flight his irons, move it however you want him to move it and is one of just two golfers averaging 2.0 strokes gained or better per round this calendar year (Spieth is the other). He finished great last week at the Byron Nelson, and it really does seem like it's time for him to make the leap here. Bonus points because this is one of the few events where he could pull the dinghy up to the beach and vibe all the way back to Jupiter with a massive trophy buckled next to him if he wants.

11. Xander Schauffele (T10 in 2020): He has found the least amount of success here of any of the four majors (not saying a lot, considering that includes two top-20 finishes in four tries). His game should stand up at a place like Kiawah (because it basically does anywhere). I do think Schauffele will win a major championship, but I'm having a tough time shaking that shot on No. 16 at the Masters with the tournament truly hanging in the balance.

12. Patrick Reed (T2 in 2017): Reed probably wants it to absolutely howl because, if this turns into a short-game contest, he's well-armed. Also, trying to imagine a golf world where Reed is a two-time major winner but Adam Scott is not.

13. Tony Finau (T4 in 2020): I do not generally believe in the whole "he just cannot win the big one" narrative, but I do think it's maybe more true of Finau than anyone else. Finau has the talent to lay Pete Dye's seaside creation to ruin, but he barely makes the list because he's so hard to trust late in an event.

14. Scottie Scheffler (T4 in 2020): Plays big-boy golf courses well and played in the final pairing at TPC Harding Park last August. I worry that his iron play is maybe not quite elite enough, but he makes up for it by putting himself in great spots off the tee. Big Ryder Cup stretch coming up for him.

15. Paul Casey (T2 in 2020): Casey is making a run at the Sergio Garcia Memorial Award of most top 25s without a major win. Casey is currently at 22. Garcia was at 34 before his Masters victory (Lee Westwood has 33). Coincidentally, Casey's best-ever finish at a major came at the PGA last fall when he finished T2 behind Morikawa.

16. Tyrrell Hatton (T10 in 2018): He's been one of the best ball-strikers in the world all year (good) but has missed the cut at three of his last four major championships (bad). Hatton is coming in off a top-20 finish at the Masters, though, and I trust ball-strikers with some form far more than I trust past history at other courses in other events. Cannot wait for him to go full fake shotgun at a gull over the Atlantic.

17. Matt Wallace (T3 in 2019): He's been sneaky good so far in 2021, and we have apparently arrived at the England portion of this list with Casey, Hatton and Wallace in consecutive order.

18. Sam Burns (T29 in 2019): I think Burns might think he's the best player alive right now after losing to one golfer in his last two starts, which is not the most important thing in the world, but it's not nothing either. My only hesitation here is that he's only played in one major since the start of 2019. Still, you cannot deny the heater he's been on over the last month, and he could certainly ride some great ball-striking to a victory at Kiawah.

19. Keegan Bradley (Won in 2011): Bradley is another golfer who won his debut way back in 2011. His form of late has been tremendous, and he has top-30 finishes in each of his last six events, including a near-win at the Valspar Championship when Burns beat him out. His tee-to-green game has been among the best in the world for the last three months. Of course, he'll need the putter to cooperate, which is always a concerning way to discuss his odds of winning.

20. Patrick Cantlay (T3 in 2019): Two interesting trends for him. The first is that he does not have a top 10 at a major since the 2019 PGA. The second is that he does not have a made cut at a stroke-play event since the Genesis Invitational. I hesitate to leave somebody with his talent level off this list, but he's been abysmal (for him) of late.

T21. Webb Simpson (T13 in 2016), Corey Conners (T64 in 2019): A couple guys I wanted to get on the list. Length and the PGA are not really Simpson's wheelhouse, and he's coming in off a withdrawal from the Wells Fargo Championship because of a neck injury. However, I had to include him because only J.T. and Morikawa have been better from tee to green over the last three months. Conners is an absolute flusher who's built for places like Kiawah. Still, there's concern that he has no top 50s in majors other than at Augusta.