In the United States of America, we believe in knowing, for sure, once and for all, who is "the best." That's why we have national championships in every major sport. The NBA calls it "The Finals", MLB calls it "The World Series" and the NFL calls it "The Super Bowl." But really, they're all simply national championships. College basketball's got one that gives us an undisputed champion, as does college baseball, college hockey, college footba [e] um, lacrosse. So while there are four majors in the world of golf, only one is the national championship of these United States, and that's the U.S. Open.

Call it patriotic pride or media-savvy marketing, but the U.S. Open is also the venue for the second installment of the ESPN Best Ball Challenge. Many of you have played before, but if it's your first time, here are the basics: The point of the game is to put together a foursome of golfers who will combine for the best score each day using "best ball" rules. Basically, each player's scorecard is combined and you get the lowest score of any of your four players on each hole, so if three of your pros bogey a par 5 and the other one holes out his second shot from 260 yards away, you get credit for the ultra-rare double-eagle, also known as an albatross. You have 50 million fantasy bucks to spend on your ideal foursome, and while that sounds like a lot unless you're a member of the Gates family, it's a budget that will prevent you from simply loading up on the four top players in the field. Like everyone else in this economy, you've got a limited amount to spend and if you go over your limit, your fantasy credit card will be rejected, confiscated and cut up by the smug-looking clerk at the register.

However, unlike in past incarnations of ESPN Best Ball, you now have the ability to switch the players on your roster and replace them with anyone who you think is playing better. If you've got Rocco Mediate -- who came within an eyelash of a massive upset victory at the U.S. Open in 2008 -- and he can't come within an eyelash of a birdie, you can swap him out between rounds for anyone of equal or lesser value. It's up to you. MORE