Golfer Jordan Spieth has a 'safe word' with his caddie to keep him from getting too negative

• Jordan Spieth has a safe word with his caddie that helps him avoid getting negative.
• Spieth said that if he's ever getting too down on himself, caddie Michael Greller has a word to say.
• If Greller says the safe word, Spieth isn't allowed to talk until the next shot.

Jordan Spieth and caddie Michael Greller have a relationship unlike any other on the PGA Tour.

Both men are expressive, and when talking through a potential decision on the course, the two can sometimes argue like an old married couple.

Also, like an old married couple, the duo has a safe word - no, not that kind.

Speaking with the podcast No Laying Up, Spieth explained that Greller had a safe word that he would use to help Spieth shut up on the course if he was getting too negative on himself.

"When you've got a microphone on you all the time, there's certainly been clips, there's been times where I've certainly regretted the way I've approached situations," Spieth said.

Spieth explained that there are moments on the course where had he been alone, he'd be able to keep his frustrations to himself. However, with Greller, he has someone to talk to if a shot goes awry.

"I can get into negative banter because while I would normally be able to compartmentalize and figure it out by the next shot, I feel like I've got to justify it to Michael," Spieth said.

Just having someone to bounce off of can sometimes lead to a spiral of negativity, so Spieth and Greller decided to figure out a way to prevent such a spiral from derailing a round.

"We've kind of developed this system where if it feels like I've just been over-talking, he's got a kind of safe word where he just says something, and then I can't talk anymore until the next shot," Spieth said. "It's only when I've gone really overboard, and he knows what it is. It's only when I'm just repeating myself, going in a circle."

While Spieth didn't reveal what the safe word was, it was clear that its existence was a sign of the strength of the relationship he and Greller had rather than the strain.

"It's fun talking through shots and situations with [Michael]; we've had the highest highs and some of the lowest lows together," Spieth said. "There's no one else I'd rather have on the bag when it's crunch time on a Saturday or a Sunday, and I'm trying to do a little too much, or I'm asking a question about what's behind that pin, and he paints a clear picture for me to feel confident going into it."