ATLANTA (AP) Tiger Woods never bothered to study all the possibilities of the FedEx Cup.
That's why he was stunned to learn that he could win three straight playoff events and still not be assured of winning the big prize. And despite his six victories this year - twice as many as anyone else - there were four other players at the Tour Championship who could win the final tournament and beat him out for the FedEx Cup.
Instead, he has stuck to a familiar formula - just go win the tournament.
Woods executed that part to near-perfection over two days at East Lake, in sweltering heat that has made the greens especially firm. And even though he missed two short putts on the closing holes, then took bogey on the 18th, he still carved out a 2-under 68 on Friday that gave him a one-shot lead going into the weekend.
"The day as a whole was a good day," Woods said. "I shot under par, and I got myself ... in the lead."
Next up are a pair of familiar foes.
Woods was at 5-under 135 and had a one-shot lead over Padraig Harrington (69) and Sean O'Hair (70). He is friendly with both of them in different ways.
Woods has immense respect for Harrington because of the Irishman's work ethic, which has led to three major championships over the last three years. They have spent plenty of time together this year, and Saturday morning will be the ninth time they have been in the same group on the PGA Tour. Woods has outscored him on all but one occasion.
Woods thinks enough of O'Hair that he spent extra time during their back-nine practice round Wednesday to impart some advice on putting. They were paired together in the final round of the Arnold Palmer Invitational in March, when Woods rallied from a five-shot deficit for his first victory following knee surgery. O'Hair found redemption two months later at Quail Hollow, when he trailed Woods by one shot and the leader by three, and won his biggest PGA Tour event to date.
There is more than a threesome with a chance to win, however.
Ernie Els made a few good putts, a reminder of what this game can be all about. After missing everything in the opening round of 71, he made everything Friday for a 66 that put him only two shots out of the lead.
Right behind was Kenny Perry, who figured out how to cope with the heat and shot 66 to finish on 2-under 138, along with Jerry Kelly. There were 10 players within four shots of Woods' lead, including a trio of major champions this year - Angel Cabrera, Lucas Glover and Stewart Cink - at 1-under 139.
The Tour Championship promised to be compelling because so many players had a chance to win the FedEx Cup and its $10 million bonus. Now, the tournament might be the best part of the weekend.
Woods seized control of the FedEx Cup because all he has to do is win. None of the other four players who were among the top five seeds - and who only needed to win the tournament to collect the big prize - were among the top 10.
Harrington would have to win the Tour Championship and have Woods finish in a two-way tie for second. O'Hair needs a victory and for Woods to be in at least a three-way tie for second.
"If I win this golf tournament and Tiger finishes second ... I'm going to be throwing a big party and jumping with joy," O'Hair said. "If I don't win the 10 million bucks, I should have played better. A win is a win. Let's face it, I've got to win this golf tournament to win the $10 million. If I do my job, that's all I can do."
Harrington feels the same way, not so much about the potentially big payoff, rather the chance to beat Woods.
"When you're out there on the golf course, he's just another guy," Harrington said. "You can't put him up on a pedestal like that. It wouldn't help in that sense."
Harrington got a first-hand look of how anything can happen.
Playing alongside Woods on Friday, he figured Woods was about to expand his lead with a pair of sensational shots on consecutive holes - one was a 5-wood up the hill on the par-5 15th that barely cleared a bunker and stopped just over 4 feet away for an eagle putt, the other was a short iron that covered the flag on the 16th and stopped 4 feet away.
Woods missed them both.
"Obviously, I didn't expect him to miss two in a row," Harrington said after a 69. "I looked up at the stats on the board just before he hit it, and he's No.1 from that range. I don't think he misses two in a row all year. That's probably for sure he hasn't missed two in a row on the year. So it was a surprise."
Woods attributed the first miss to being confused by the grain that went to the left and a slope that went to the right. The grain won, and the putt caught the left lip. On the next putt, Woods had spike marks on his line and tried to jam the putt inside the marks and right into the hole, but the grain pulled it farther left and he caught another lip.
He made his share of putts, too, like the 8-footer for par on the 17th, and three straight birdies at the turn. It all evens out, and Woods is in spot that left him with few complaints - atop the leaderboard.
The trick now is to stay there, which doesn't figure to be easy with so many players crammed in behind him.