Inside Jon Rahm's putter switch before U.S. Open win

His 18-foot, curling left-to-righter breaks toward the hole, eyes locked on its path, Jon Rahm raises his Odyssey Rossie S putter and unleashes a jubilant fist pump as his ball dives into the darkness.

We’ve seen the highlight how many times in the handful of days that have passed since that putt clinched Rahm’s U.S. Open victory?

It’s hard to imagine that the world No. 1 only switched into the flatstick the tournament prior to the U.S. Open. It’s surprising, too, that the mid-mallet model he settled on was a significant departure from the gigantic rear-center of gravity, high MOI mallet he had been using for months.

So, how did we get here? How did Rahmbo look more like 2008 Sunday Tiger Woods on the 72nd at Torrey Pines and less like a golfer who was so frustrated with his putting he went back to the drawing board less than a month ago?

The week prior to the Memorial Tournament presented by Workday, Rahm visited with Callaway head of tour operations Tim Reed and Odyssey rep Joe Toulon at the Ely Callaway Performance Center in Carlsbad, California, to test putters. There, Rahm was most intrigued by an Odyssey Rossie S mid-mallet putter. He remained happy with the Microhinge Star insert that had been, well, inserted into his 2-Ball Ten at the PGA Championship, so Toulon and company had the Rossie built with the Microhinge.

After evaluation on SAM PuttLab and Quintic (two putting analysis systems), it was clear the Rossie performed better than the higher-MOI, rear-CG 2-Ball Ten he had been putting with since joining Callaway’s tour staff in January. And as evidenced by his barnstorming three rounds at the Memorial Tournament and his clutch putt-filled win at the U.S. Open, the Spaniard’s putting performance was indeed elevated.

For the inside story of Rahm’s Rossie S, GolfWRX spoke with Odyssey tour rep Joe Toulon.

GolfWRX: When Rahm signed with Callaway, he was using a putter that looked very much like the Odyssey 2-Ball Ten he ultimately put in the bag. It intuitively made sense that’d be his choice, but he switched to a different putter at the Memorial. Why?

Joe Toulon: When he came into our putter studio in January, he hadn’t really been putting great. He was anxious to get into something. We had, probably, 20 putters made up for him, and the whole time, we were thinking the 2-Ball Ten with the S-neck would be the winner because it was similar to what he was using coming in.

But through that process, you have to listen to what the player is saying and how they’re saying it. He was struggling with setup and how his putter sat on the ground...and he found himself fidgeting.

In his college days, he used a 2-Ball. So the 2-Ball Ten, the way it sat on the ground for him was the reason he gravitated toward that. He felt comfortable with it...and with his path, he squared it up a little bit more and hit more putts in the center of the face.

The last thing we did with that putter was change to a White Hot insert. He’s such a feel player, and he told us that White Hot felt good at impact.

So that’s what he switched to at the Farmers Insurance Open and used through the PGA Championship.

GolfWRX: And then he made a minor modification at the PGA Championship…

JT: So, we follow player stats very, very closely. We talk to players, caddies, and agents. We always want to see what the feel is with the putter (and every club, really). His putting didn’t really change much from the beginning of the year, over time, he just grew frustrated as he expected he’d start making those 8-12 footers. He never really had a hot week with it [the Odyssey 2-Ball Ten putter]. He was always right around zero strokes gained: putting for the week. So, looking at his stats, we thought if the putter could just get relatively hot, he was doing everything else great.

We had a meeting before the PGA Championship with Jon, his caddie, and a couple of other people, and we wanted to dive deep into the stats and what he was feeling out on the course and what his caddie was seeing.

We started hearing him say his speed had been a little bit off, so we made an insert change in his 2-Ball Ten [White Hot to Microhinge Star]. We didn’t want to change the whole putter because it was the week of the PGA Championship.

We were pretty excited about what we were seeing, but then after his round Saturday, he told us it would be his last round using the putter.

GolfWRX: Wow. Back to the drawing board then! What direction do you go from there?

JT: The Rossie was one of the putters I had made for him back in January, and I could just tell, watching him look at all the putters and listing to his initial thoughts, it was all positive with that one, and he kept kind of looking back at it, so that was something I built up for him along with a couple of others.

We kind of pieced everything together knowing that he’s not a very linear person; he doesn’t like lines on his putter, and we knew he liked the insert. He liked the speed off the face, the feel, and the roll, so we knew we were going to go with that insert. And we wanted to go back to something with an S-neck so he could feel the face rotate.

The 2-Ball Ten, where the center of gravity is in that putter is further back. Over time, we started to get the sense that wasn’t working well with him wanting to feel the face rotate. And over time, that kind of altered his stroke a little bit to the point where he didn’t look comfortable over the ball. So, we wanted to give him something with the CG a little more forward.

He came into the test center Thursday and Friday (of the Charles Schwab Challenge) to look at putters and dial in the right one, but Thursday when he came, he was in love with the Rossie and we got him on Quintic and PuttLab and made sure the numbers were good.

At that point, we may have made a slight loft adjustment to help launch angle, but that was it. It was pretty amazing just to see how confident and comfortable he looked with that putter in his hands. He was a completely different person on the greens.

GolfWRX: So clearly a different putter and better performance, but why/how was it working better for him?

JT: Basically, he was just feeling the face a little bit more, which made him more attuned to face angle and how it was rotating in his stroke. He was feeling like a more “natural” putter again.

Jon Rahm putter specs

Putter: Odyssey White Hot OG Rossie S
Insert: Micro Hinge Star
Shaft: Steel stepped
Grip: Odyssey 56 pistol
Length: 37 inches
Loft: 2.5 degrees
Lie: 68-degrees
Weight: 544 grams