Tiger Woods has won seven straight tournaments when he's taken a lead into the final round.

Back in the old days, when Woods first emerged as a rookie on the PGA Tour, he talked of teeing it up to win every week, expecting that he could do so.

When he won the 1997 Masters by 12 shots, he said winning all four major championships in the same year was possible, something he'd relish pursuing.

More than two years later, Woods, 23, is still in search of his second major championship, one that could be forthcoming at the PGA Championship.

Woods shot 68 on Saturday at Medinah, grabbing a share of the lead on a day when he was not at his best. He is tied with Mike Weir, a left-hander who has shown plenty of grit but has never won a PGA Tour event.

This is a mismatch if there ever was one, but golf offers no guarantees.

Woods knows all too well. Despite some excellent play in the last two majors, he could not break through and win.

A final-round score of 70 at last month's British Open would have put him in a playoff, but he tied for seventh, four shots back. He tied for third at the U.S. Open, missing two crucial putts down the stretch. He tied for 10th at last year's PGA Championship.

"All I can do is keep giving myself chances," Woods said. "It's part of the game. Eventually, either someone else is going to make a mistake and I'm going to sneak into a victory or I'm going to outplay someone."

Woods has rarely failed from this position. You have to go back to his third tournament as a pro to find a time where he couldn't bring home the hardware after taking the third-round lead. That was at the 1996 Quad Cities Classic. Two tournaments later, Woods was winning his first PGA Tour event.

Since then, he's held or shared the third-round lead seven times and gone on to win each tournament. The most recent was at last month's Western Open, some 20 miles from here at Cog Hill. Ironically, Woods was paired with Weir in the final twosome. But then, he took a four-shot advantage into the final round. This time, they are tied.

"I enjoy being in the position where everyone is trying to beat me," he said. "I look at it like, if you have a lead, you have a cushion. Other players are going to have to shoot that much better in order to catch you. That's the approach I've always taken.

"But I'm tied for the lead. There is someone right there."

Woods has had a strong summer, fluctuating between the No. 1 and 2 spots in the World Ranking with David Duval. He's finished out of the top 20 just twice in 16 tournaments this year. He's won the Memorial and the Western Open -- after winning the Buick Invitational earlier in the year -- finished tied for third at the U.S. Open and tied for seventh at the British Open.

If a few more putts drop in those major championships, who knows? Woods might be going for his third major of the year, thinking more about Nicklaus' professional record of 18.

"I look at Jack's career," Woods said. "And Jack finished second in 19 majors. How did he feel about it, losing that many times? But he also won 18. He kept giving himself chances."

Woods used to say that he compared himself to Jack Nicklaus, that he wanted to match his records. But already, that talk is tapering. Nicklaus had three major titles by age 24, a number Woods can't yet touch. Nicklaus had 12 PGA Tour titles at age 24, while Woods has 10 and counting.

"Our fields are a lot deeper now," Woods said. "For instance, look at Paul Lawrie winning the British Open. What was he ranked (159) in the world? (Nicklaus) didn't have too many players winning majors that came out of nowhere. The fields weren't as deep. They had great players, but they didn't have the quality of field."

With that said, Woods has managed to give himself a chance in three straight majors. And with Nick Price the only player within seven shots of him who has won a major championship, this is a golden opportunity.

"I have to go ahead and take care of my own business first before I can ever start worrying about kicking in the door and winning my second major," Woods said.

Bob Harig, who covers golf for the St. Petersburg Times, writes a column every Tuesday for ESPN Golf Online.