Remember what happened last year at the Tour Championship? Dustin Johnson came in with the No. 1 ranking in the FedEx Cup standings but shot a 73 on Sunday to fall to T6 overall. He was still in contention for the $10 million first prize, though, but he needed Ryan Moore or Kevin Chappell to win a playoff against Rory McIlroy. Otherwise, he'd get "just" $3 million.

"It was very interesting," said Johnson. "I don't think I've ever rooted so hard for another player to win a tournament, that's for sure. I mean, it was interesting to watch, but it was fun. I had a good time doing it. I still give Chappy, because he's a buddy of mine, so I still jab at him every once in a while about how much he cost me."

McIlroy, of course, went on to win the event with a thrilling putt four holes into the playoff, and he took home the $10 million.

This year's FedEx Cup No. 1, Jordan Spieth, said he's prepared for a similar scenario this year. Spieth controls his own destiny, meaning that if he wins the Tour Championship, the FedEx Cup is also his. But he doesn't have to win the Tour Championship to take home the $10 million bonus.

"I think there's a likelihood that I'll be in that situation this year," Spieth said on Tuesday. "I'm not sure. I don't know who the Rory will be. That might change the way you look at things, too. It's tough. I mean he's sitting there not able to control a $7 million difference, like that doesn't happen anywhere else. 

"It's like having a $7 million bet on a fight that you're not even taking part in. It's like I would be really nervous but at that point I'm already out of the tournament so I could probably have a few beers to calm me down, I don't know. I imagine if somebody else made a putt for me to win a difference of $7 million, I'll probably celebrate accordingly with a scream or a fist pump or something. But it's an odd scenario and it's likely to happen at this tournament and it has."

The last time it happened was in 2009 when Phil Mickelson won the Tour Championship, but Tiger Woods took home the FedEx Cup. The points have been changed since then, though, so it's less likely than it used to be. But it could still happen.

Let's set up a hypothetical here. Let's say Spieth closes on Sunday with a 66 to finish in fourth place by himself. Then Rickie Fowler and Matt Kuchar are duking it out for the tournament crown. If Fowler wins that hypothetical, he takes home the FedEx Cup as well. If Kuchar wins, Spieth takes it. It happened last year, and it would be fun (and weird) as hell again this time around.

Either way, Spieth said he's treating this week as if it's a major championship, even though he noted that this event is a notch below the four big ones. 

"I think it's more physical just how you work, how much you're working, what I'm doing off the course physically," said Spieth. "I understand that this week there's a lot on the line, it's essentially a major after coming off of a pretty hectic schedule the last six, seven weeks. So I'm trying to conserve energy.

"If you get off to a great start, great, but you get into the thick of things here on the weekend and it takes a lot out of you. So maintaining that kind of energy physically is very important this week but it also goes into how we're practicing. Things feel good. If it were a major championship I would be very pleased with where things are on a Tuesday. Mainly at this point it's conserving energy. [In] 2014 and 2016, especially 2014 I remember being completely worn out by the time I got to the Tour Championship."

That's not the case this year as Spieth has finished in the top 10 of each of the first three playoff events, including two runner-up finishes. If he wins his second Tour Championship and FedEx Cup this weekend, he would be the only player besides Tiger Woods to do that. And that's a phrase I think we'll be using a lot when it comes to Spieth over the next 20 years.