This year's WGC-Match Play has a new format and a new event. There are pools of four-seeded players in each group, with one winner from each of the 16 pools -- which were chosen at random with ping-pong balls -- advancing to the quarterfinals, ala the World Cup.
Here are the nine "pool-play" match ups we're most looking forward to.
Group 1: Rory McIlroy vs. Billy Horschel
The last time these two played each other in match play, they were representing their respective sides at the 2007 Walker Cup. Horschel got the best of McIlroy that week and got under the Northern Irishman's skin for his on-course celebrations. The two claimed they've put the matter behind them, but that doesn't mean they won't each get a little extra pleasure by beating the other at Harding Park. --Alex Myers
Group 2: Jordan Spieth vs. Mikko Ilonen
On paper, this might look like a mismatch between the recent Masters champ and the veteran European Tour member. Think again. For one thing, as we've seen year after year, no one is a safe bet in this event. And secondly, Ilonen has more match play chops than you might realize. The Finnish player had his finest season in 2014, winning twice, including the Volvo World Match Play Championship, in which he bested Henrik Stenson in the final. Of course, Spieth is the No. 2 player in the world, though, and he's had plenty of match play success as a two-time U.S. Junior Amateur champ.* --A.M.*
Group 7: Jason Day vs. Zach Johnson
Day is the defending champion and owns a 14-3 record in the Match Play -- which along with his stellar 3-1 record at the last Presidents Cup -- makes him one of the most feared match-play opponents in the world. But when he faces Zach Johnson, he's going up against one of the most fearless players in the world. Johnson can get hot with the putter, and he just recently switched back to his trusted Seemore. This might be an upset if ZJ wins but it wouldn't be hugely surprising to us. --Stephen Hennessey
Group 8: Dustin Johnson vs. Victor Dubuisson
Dig the long ball? These are two of the longest hitters in the world. Dubuisson announced himself to golf fans around the world with his uncanny recovery shots in last year's WGC-Match Play final when he took Jason Day to 23 holes. And he took down another fellow bomber, Bubba Watson, last year. D.J. is 2-6 in past WGC-Match Plays, but his game wasn't really suited to the past venue, the Ritz-Carlton Dove Mountain. He's been solid in Ryder Cups and Presidents Cups and has been playing great in 2015, so this should be an interesting match. --S.H.
Group 11: Jimmy Walker vs. Ian Poulter
Pitting perhaps, the best golfer on the planet in 2015 not named Jordan Spieth in Walker versus a Ryder Cup legend in Poulter. The Englishman has more pro match play experience in singles than anyone in the field with a career record of 34-14-5. But Walker proved himself in this format at his Ryder Cup debut last fall. Still, as a No. 1 seed, no one could blame him for feeling unlucky for drawing Poulter right away. --A.M.
Group 13: Rickie Fowler vs. Graeme McDowell
There's a ton of match-play experience in this group. Rickie is a two-time Ryder Cupper and owns a 7-1 record in two Walker Cups. McDowell is winning the clinching points in his 2010 Ryder Cup defeat over Hunter Mahan. But McDowell quietly went 3-0 in 2014 at Gleneagles. McDowell hasn't played great this year, but the guy thrives in match play. --S.H.
Group 14: Matt Kuchar vs. Hunter Mahan
The U.S. Ryder Cup teammates will make up the only group-play match involving two former champions of this event. Other than Jason Day, Kuchar has the best current match play winning percentage (69) of anyone in the field. Mahan isn't far behind at No. 4 (66 percent) and he nearly matched Tiger Woods as the only repeat winner of this event. Who stopped him in the 2013 final? Kuchar. --A.M.