Is he really just a paper Tiger?

There is a vulnerability to Tiger Woods.

A fragility that shows itself at the most inopportune of times; like, for example, on weekends at major championships.

Maybe it was always there.

Maybe Woods was so good at suppressing his doubts and reservations, his human frailties, that he could keep them hidden — even from himself — beneath that icy, focused stare for all those years during all those victories.

As I walked across the massive expanse of Kiawah Island’s front nine on a hot, sticky Saturday afternoon, it became clear that Woods can no longer mask his vulnerabilities.

Not from us, and maybe not from himself, either.

As I watched him stumble for the third straight major Saturday with that elusive 15th victory in sight, I thought about something told to me recently by someone who was once close to Woods.

“Even when it’s going good he kind of looks like he’s faking his confidence, or trying to convince himself that he’s confident,” the former insider told me.

It struck me on Saturday that not only was the legendary Woods confidence gone, but that it left when the moment got too big; the stage too grand.

Yes, Woods has won three times on the PGA tour this season, but this is a major. This means a lot to him, much more that regular tournaments.

When he stepped on the tee at the PGA Championship, there was much on the line — he hasn’t won a major since before the scandal — and has thrown away opportunities at both the US Open, where he led going into the weekend, and the British Open, when he started Saturday in the penultimate pairing.

He was tied for the lead here through two rounds with Vijay Singh, who at 49 was never going to be the threat he once was to Woods’ reign.

The old Tiger would’ve seized the moment.

This Tiger just looked like he didn’t know how.

After Singh drained a 25 footer for birdie on the opening hole, Woods’ birdie try from the left fringe, 15 feet away, was hit too hard and never really had a chance.

He wasn’t happy.

On the par-5 second — a routine birdie hole with Saturday’s helping wind — Woods was in perfect position but played a marginal chip, then after watching Singh putt on his line, missed again from 15 feet.

Again, more signs of agitation.

On the third, Woods decided not to try driving the green — it played only 305 yards — and the decision seemed vindicated when he put a wedge to three-and-a-half feet.

But he missed that putt and his reaction was so dramatic — he leaned over on the same putter that had been magical for two days and shook his head in disgust — that even veteran Tiger watchers were surprised.

I can’t ever recall Woods being so annoyed so soon in a round.

Did he not have 33 holes to play in this championship?

Or was he already sensing the day would not go well?

The exasperation he felt clearly affected Woods, who then pull hooked his tee shot on the fourth into the galleries, hitting a woman.

He hooked his approach out of the rough, too, but was still in a relatively good place to save par.

Except the sharp short game he’d displayed for two days suddenly abandoned him; his effort was high on theatrical value, but not so good on a practical level, not even making the green.

He made bogey while others were making birdies. Rory McIlroy was four-under par through nine holes to be six-under par — and tied for the lead — for the tournament.

Low numbers were to be had at Kiawah — Steve Stricker shooting 67, as did Bo Van Pelt while Padraig Harrington had a 69.

Woods, meanwhile, was going backward. Another pull hook — and another poor flop — led to another bogey on the par-3 fifth.

After a par on the sixth, Woods sliced a drive on the seventh, into an awful lie in one of Kiawah’s many sandy areas — that in other places might be called bunkers — and after shanking a difficult shot finished the hole by dropping another shot when he couldn’t save par from 10 feet.

On the eighth, a par three, he missed the green and the round was clearly getting away from Woods when, mercifully, he got the time out he needed.

The skies darkened as only, it seems, they can in South Carolina at this time of year and after the heavens opened, play was suspended.

Woods gets to regroup and return on Sunday morning; only instead of being tied for the lead, he’ll be five shots behind McIlroy and Singh, with 10 players between him and the lead.

"I got off to a rough start today and couldn’t get anything going,” he said.

“I’ll come back tomorrow morning and see what happens. There are a lot of holes left to play."

But how will he play them?