Cover photo: Rich Schultz/Getty Images

Don't challenge Tiger Woods to a bet. Unless you want him to call you out on it right away. 

Phil Mickelson decided to bet Tiger Woods a cool $100,000 that he would birdie the first hole ahead of The Match, which will pit Tiger against Phil in a $9 million winner-take-all match play event.  

Well, Tiger not only accepted the bet, but he also doubled down. 

Mickelson might have been confident he was going to birdie the first hole, but clearly, Woods is even more confident he won't birdie the first hole. Guess we'll find out soon. 

Tiger and Phil are, of course, no strangers to betting on the course. Phil is notorious for organizing Monday betting matches on the PGA Tour, while Tiger and Michael Jordan have reportedly thrown down some serious money in matches against each other. 

With $9 million on the line in this match, and plenty of dough thrown around between the two in previous matches, $200K on birding the first doesn't seem like a big deal. The Question is: Who you got?