The putter is an Odyssey ProType 18ix, a half-mallet that Odyssey sells only in Japan, but Mickelson was smitten by the shape and thought it might help him avoid pushing and pulling putts more effectively than his blade putter. He also liked the high-toed look and the face insert, which is very similar to the insert in Odyssey White Hot putters.
There was just one problem with the club -- it was only made in right-handed versions.
Enter Austie Rollinson, the principal designer at Callaway Golf. Rollinson got Odyssey clubmakers in California to start milling a left-handed version of the putter especially for Mickelson. It took a few days to create, and on the Friday after Mickelson returned to the United States from England, he and Rollinson worked on the putter for more than an hour. They bent, tweaked and adjusted until the putter perfectly suited Mickelson's setup and eyes.
Rollinson and Mickelson also experimented with different combinations of adjustable weights in the sole of the putter. The Japanese putter is available in 340-, 350- and 360-gram versions, but golfers can further modify it to suit their liking. Rollinson says that Mickelson tinkered with different weight combinations, but as you can see, he has decided to go with two 15-gram weights.
According to Rollinson, the lie angle of Mickelson's putter is 74°, and it has 3° of loft, the same numbers as his old putter.
According to Mickelson's caddie, Jim "Bones" Mackay, the putter was first put to use in competition on Friday at last week's WGC-Bridgestone Invitational in Akron, Ohio. Phil liked it and continued to use it through the weekend.
"I'm a little surprised that it went in the bag as quickly as it did," Rollinson said. "But Phil knows what he likes."
(Related Photos: More images of Mickelson's new Odyssey putter)