No one seems to know exactly what’s wrong, least of all Tiger Woods.

He’s gone from a very respectable start to the season, tied for fourth at the pressure-packed Masters in April, to the worst 72 holes he’s ever turned in as a pro by nearly every statistical measure. If it was just a swing adjustment, it would have been taken care of long before now.

The speculation that followed Woods’ driveway demolition derby last November has waxed and waned. But a consensus emerged from the weekend that he’s hit rock-bottom as a golfer, which became a tripwire for yet another round of overwrought analysis that he was on the ropes as a human being, too.

No one but Woods knows what’s going on between his ears, yet it’s hardly speculative to say that some of the tension inside there has leaked into his golf game. He’s hardly the first guy whose job performance took a nosedive in the middle of divorce proceedings, and he won’t be the last to get his bearings back, either. The only question is when not if.

Bookmakers, who can’t afford to be sympathetic, don’t seem overly concerned yet. The Las Vegas Hilton Sports Book listed Woods at 12-1 to win this weekend’s PGA Championship at Whistling Straits, just behind favorite Phil Mickelson at 10-1. The rest of the field is 15-1.

At first glance, the odds make you wonder whether the TV sets at the sports book were working Sunday, when Woods walked off the 18th green at the Bridgestone Invitation after a 77 that left him a staggering 18-over-par. (And for that matter, a few hours later when Mickelson finished. With his best chance ever to wrest the No. 1 world ranking from Woods, Avis — er, Lefty — shot 78.)

Then again, betting lines are set not to predict the winner so much as attract the maximum number of wagers on everybody in the field. And when the Bridgestone began, Woods was a 6-1 favorite in the PGA.

“We wanted to see if this would attract bettors. If they lay off,” Hilton’s Jeff Sherman said over the phone Monday, “you could see him drop to 15-1.”

There are plenty of ways to measure how far the mighty have fallen, but none may be a better barometer than Woods downplaying his own chances. Absent Sunday for maybe the first time since his private life imploded was his public bravado. Every time he doesn’t win a tournament somewhere, Woods writes it off as one more important piece of preparation for the only tournaments he really cares about — the majors.

On this Sunday, he didn’t even try that alibi. He was coming off a Firestone course where he should have played well — Woods had won seven times in his last nine starts there — and heading directly to the site of the season’s final major in Wisconsin. Instead of saying how close his game was to winning the PGA, Woods worried aloud whether he could recover in time to deserve a spot on the U.S. Ryder Cup team — and those matches don’t begin until Oct. 1.

“I wouldn’t help the team if I’m playing like this,” he said. “No one would help the team if they’re shooting 18-over par.”

Woods could make the question of his selection moot by winning the PGA, or playing well enough there to climb two spots up the Ryder Cup points list from his current perch at 10. If not, plenty of smart golf people — beginning with past U.S. captains Paul Azinger and Curtis Strange — have already gone on the record saying current captain Corey Pavin should use of his two wild-card picks to add Woods to the squad — but only if he’s properly motivated.

At the 2009 Memorial, Woods talked about that subject and a valuable lesson he learned pitching in during a practice session with Michael Jordan.

“I remember the countless hours I spent with Michael in the gym feeding him balls,” he said. “He would just shoot all night, and you thought that, yeah, he just showed up to the game and off he went and scored 45 and went home.”

Woods said something else that day about how Jordan and other elite athletes prepared for their turn in the spotlight, but he might as well have been talking about himself.

“I think their work ethic and how they prepare and what they have to do in the offseason and during the season — no one has any idea,” Woods said.

Those close to Woods remember a time when his practice time was almost sacrosanct, when business and everything else had to be put on hold for two weeks or more at a time, if that’s what his playing schedule demanded.

No more.

One guess is that it won’t change until the divorce papers are signed — whenever that is — but there’s a gauge that could be useful in the meantime. Woods has let slip that he’s practicing less, that he has more distractions than ever and as a result less and less time to prepare. Until that pendulum swings back in the other direction, my guess is that not much else about Woods’ game is going to change.