Match Play Supporters Say:
The PGA Championship is considered the weakest of the four majors. Switching it to match play would give it a big boost and set it apart from the other majors. Match play would give the PGA Championship an identity. Match play is a more exciting style of play, a style of play where fans can hang on every shot, even early in the matches.
Major upsets and dark-horse winners provide a spark. The possibility of something out of the ordinary happening - Peter O'Malley defeating Tiger Woods in the first round, for example - is always present.
The explosive popularity of the Ryder Cup proves that match play is a big hit with fans.
The success of the WGC Match Play Championship proves that a match play tournament can draw big ratings.
Match Play Opponents Say:
The PGA Championship (and other majors) already has an identity: it's a major, and there's no reason to mess with it. Match play does draw fans in earlier in the matches, but stroke play keeps fans more interested late in matches. If a golfer is 5-up with 6 holes to play, the winner is almost assuredly known.
Early round upsets are a bad thing, not a good thing. If Tiger Woods or Phil Mickelson loses early in match play, they're outta there. In stroke play, Woods or Mickelson can shoot a first-round 76 but still battle back into contention.
The Ryder Cup's popularity has to do with emotion fueled by national pride, not format. In the Ryder Cup, no one is eliminated. All players remain in the competition, playing to the final day.
Match play can draw big ratings. A Tiger Woods-Vijay Singh final would be huge. But a Shawn Micheel-Chad Campbell final wouldn't do much for anyone. At least in stroke play, even if the big stars aren't in contention, they are still around and playing.
Where It Stands
The possibility of one of the majors switching to match play is nothing more than idle chatter among golf fans and media at this point. There is no indication that any of the governing bodies of the four majors has given any thought to switching away from match play.But there are many well-connected people in the golf world who believe the idea is worth exploring, so it's one that we'll probably hear more about over the coming years.

