He hasn't broken par all summer. He has shot in the 80s his last three stroke-play events. He has no clue which way the ball is going until it leaves the tee.
But to suggest it can't get any worse is to forget Royal Troon six years ago.
Try being a major champion who goes 31 straight PGA Tour events without a paycheck.
Try taking six months off in a desperate search for a solution, then taking a patched up swing and shattered confidence to golf's oldest championship.
Rock bottom is a 92 in the opening round of the '97 British Open.
It's knowing that thousands of people watching this horror show at Troon are cracking jokes or taking pity, and trying to decide which one makes you feel worse.
Ian Baker-Finch can tell you all about rock bottom.
'I felt like I was walking naked, like the grass was taller than me,'' Baker-Finch said. 'I tried to walk with my head high. It was really hard.''
Baker-Finch cried in the locker room that afternoon, withdrew from the tournament and quit competitive golf at age 35, the prime of his career.
Duval is not there yet, not even close.
Still, Baker-Finch has noticed enough similarities that he stopped a reporter last week at the Deutsche Bank Championship and asked the question no one has been able to answer.
What's wrong with Duval?
'What happened to me ... there's a correlation to what might be happening to David,'' said Baker-Finch, an amiable Australian working as an analyst for ABC Sports.
'I lost my confidence,'' he said. 'I got to the point where I didn't even want to be out here because I was playing so poorly. I would try my hardest, but when I came out to play, I managed to find a way to miss the cut time and time again. It became a habit.''
Baker-Finch won the Colonial in 1989, played in his first Tour Championship a year later and then blew away the field in 1991 at Royal Birkdale to win the British Open, the pinnacle of his career.
His problems began in 1994 with a series of injuries _ knee, shoulder, eyes _ and he started missing the cut, 11 straight at one point.
Baker-Finch tied for 47th at Firestone that year and made $12,850.
That was the last PGA Tour check he earned.
'You know those laminated woods?'' he said. 'I always make the analogy that confidence is like those layers. You keep chipping away at it. You play poorly, another layer is gone. And when you're on that negative spiral, it's hard to put another layer back because there's no glue left.''
He sought help from nearly a dozen of the best coaches, all of them certain they had the right fix.
It only got worse.
The scores were shocking _ 12 rounds in the 80s, only two in the 60s. Bad vibes penetrated his psyche every time he finished his round and saw a group of reporters waiting next to the 18th green to learn about the latest train wreck.
'I dreaded it,'' Baker-Finch said. 'They were always asking negative questions: 'Are you coming out of your slump yet?' My whole life became negative. Not only was I searching, not only was I lost, not only was I playing poorly, but I didn't want to be out there.''
The end came in 1997, and Baker-Finch now wishes he had not stopped so soon.
He still plays at The Bear's Club at home in West Palm Beach, Fla., often in friendly games with PGA Tour players, taking their money as often as they take his.
'He flushes it,'' said Robert Allenby, who says Baker-Finch could regularly finish in the top 50 on the money list if he could just bring that game inside the ropes.
No such luck.
Curiosity got the best of Baker-Finch two years ago and he played in the Colonial. Stress followed him to the first tee, he shot 74-77 and missed the cut.
Duval has not played since he shot 80 in the first round of the PGA Championship and withdrew.
'I don't think David is anywhere near as bad as where I got to,'' Baker-Finch said. 'He's missed a few cuts, but his talent will shine through if he allows it. He's got to trust himself.''
Baker-Finch urges Duval to stick with Jack Lumpkin, whom he began seeing last month. He doesn't think Duval should change his swing, which some criticized in recent months when the scores started soaring.
'It may be unusual, but there's nothing wrong with it,'' Baker-Finch said. 'He got to be No. 1 in the world with what he had.''
Can Duval make it all the way back?
'He's always been, and he's always thought of himself, as a top player. He should be back,'' Baker-Finch said. 'But there's a lot of scar tissue. The longer he plays poorly, and the longer he thinks poorly of himself, it becomes a habit that gets further ingrained. And the harder it's going to be to get back up thehill.''
More than anyone, Baker-Finch speaks from experience.
No one is rooting harder for Duval.