LOUISVILLE, Ky. -- There is no explanation, really. At least not a good one. Phil Mickelson has always looked as if he had somewhere better to be when it came to the Ryder Cup, a guy tapping his foot and checking his watch, waiting impatiently to make his exit.
For a player of Mickelson's immense talents, it has never made any sense. He is too good to have such a poor record at this biennial competition.
Perhaps Friday was a turning point for Lefty.
And maybe his partner, Anthony Kim, had something to do with it.
Their long day at Valhalla Golf Club ended with smiles and backslapping. That's been a rare sight for Americans at recent Ryder Cups, especially for Mickelson, who -- to put it nicely -- has not been very good in this event for a long time.
"We had a lot of fun today," Mickelson said after twice coming from 3 down with Kim, earning a half point in their morning foursomes match and a full point in their afternoon four-ball. "I love playing with this guy. He has a lot of talent, a lot of game. It was fun for me to be with that youthful exuberance today. It's infectious. We played with a lot of heart and emotion. We were down in both matches and came back to win one and tied the other. It was a hard, fun day."
"This day, by far, was the best he's ever played in the Ryder Cup," said Jim "Bones" Mackay, Mickelson's longtime caddie.
So that's what it takes? Some youthful exuberance?
Mickelson truly is the grizzled veteran to Kim's wide-eyed rookie. They are 15 years apart in age, and when Mickelson played in his first Ryder Cup in 1995 (and went 3-0, by the way), Kim was a mere 10 years old.
"He's always been an idol of mine, someone I wanted to emulate," Kim said.
Who'd have thought it would take a 23-year-old to bring out the best in Mickelson? Amazingly, the 1½ points he earned tied his career high for any day.
"Maybe it helped his partner," said Europe's Padraig Harrington, who played both of his matches against the Mickelson-Kim duo and was impressed with Kim's enthusiasm. "He did enjoy himself, and that was good to see. It's not often we get a chance to get excited on the golf course, not often we feel the sort of tension and it's not often we have this sort of atmosphere. So it was good to see. I'm sure they are going to go home happy with their point and a half, and we're a little bit disappointed with just half a point."
Before Friday, Mickelson, 38, was 9-12-4 in six Ryder Cup appearances, including 1-7-1 in the last two.
At the 2002 Ryder Cup at The Belfry, he lost a crucial Sunday singles match to Wales' Philip Price. Remember him? At the 2004 event -- the same year he won his first Masters -- Mickelson was criticized for switching equipment on the eve of the Ryder Cup and practicing on another course the day before the competition. Two years ago in Ireland, Mickelson appeared ready to shut it down for the year.
So it was a different Mickelson on Friday, especially in the afternoon best-ball competition, when he was credited with seven birdies on his own ball, including a 25-foot bomb on the 17th that gave the Americans a 1-up lead over Harrington and Graeme McDowell.
"Yeah, I stole his thunder there a little bit," Mickelson said, joking about the fact that Kim had hit it in stiff to 6 feet for a birdie that would have won the hole.
"I think we are going to be pretty tough to beat," said Kim, who made the par putt on the 18th hole of the morning match to clinch a well-earned tie against Harrington and Robert Karlsson. "We are having a great time out there, and when you're having a great time, you're going to play good golf. We are looking forward to the next couple of matches."
With the help of Justin Leonard and Hunter Mahan, who teamed to win both of their matches Friday, the United States has a 5½ to 2½ lead after Day 1, still a long way from winning the Americans' first Ryder Cup since 1999 but far better than they have been at this point for a long time.
It is the first time the Americans have led after the first day since 1995, the first time they won both sessions on the opening day since 1979 and the first time they have had a three-point lead after the first day since 1979.
That's a lot of firsts, and it certainly doesn't hurt to have Mickelson on board. After all, he is the No. 2-ranked player in the world, the highest-ranked player in the event with Tiger Woods sidelined after knee surgery. As for experience, Mickelson has the most Ryder Cup matches under his belt of anyone on this year's American roster.
Sure, most of that experience has been bad, but Mickelson started out strong in the event, plus he also has played for the U.S. in the Presidents Cup.
"This was a fun day, but we have a lot more work to do," Mickelson said. "We have three more matches, and we're fortunate the U.S. has gotten off to such a good start. I love playing with this guy right here. Anthony has got this youthfulness to him and he has a lot of game and we had a lot of fun."
Bob Harig covers golf for ESPN.com. He can be reached at BobHarig@gmail.com.