"We've had a lot of fun since the first year coming in," Cain said after Friday's second round, this one at Spyglass Hill. "We've just had a blast playing together. We're both competitive and want to shoot good scores, but we've always just had a blast."
Said Bettencourt: "It's fun to play with a good friend here. We just stay relaxed and have a good time. It's hard not to at a place like this. It's great."
The Cain/Bettencourt team is in contention heading into Saturday's cut day, standing in a tie for 18th at 16-under, eight strokes off the lead in the Best Ball format.
The team of Posey and Nick Watney also is at 16-under, with Posey saying after his second round ever at the tournament: "About the same as yesterday -- some good holes, some bad holes."
The top 25 teams will make the cut, so they're both currently just under the cut line.
It's the old "ham and egg" game in the pro-am, and that's one of the things Cain likes about it, especially having developed such a rapport with Bettencourt over the years.
"The best part is having him being standard for a par, shoot for flags and hit some birdies when he can, and for me to take advantage of the stroke holes," said Cain, a 6 handicap -- obviously capable of doing some damage himself.
The Cain-Bettencourt tandem is in a foursome with Kyle Stanley and musician Charles Kelley of Lady Antebellum. That's another plus for players like Cain and Posey -- they get to meet stars from other walks of life, Posey playing alongside musician Huey Lewis in his group.
Over the last five years, the two Matts have gotten to know each other well. Bettencourt said he was thrilled to join Cain and the Giants in Kansas City for the final two games of the World Series, and he leans on his annual golfing buddy from time to time for advice, the two talking often.
And that's pretty much how the late Bing Crosby envisioned the tournament named for him. They called it the Clambake, and it was a chance to have a friendly week of golf, with celebrities interacting not only with the golfers but the gallery. Cain and Posey certainly have done that, signing autographs after (and sometimes during) their rounds and Cain giving a thumbs-up when the crowd started chanting "Let's go, Giants" after his final putt of the day.
Not every Tour golfer enjoys it, but Bettencourt does. Matt gets it, just like Matt.
"I absolutely love it," Bettencourt said. "These [amateurs] have a great time, and Charles has been great to play with this week, too, so we have a great group. Everybody's just relaxed and enjoying it. It's like a big family."
John Schlegel is a national reporter for MLB.com. You can follow him on Twitter @JohnSchlegelMLB.