What is going wrong with Michael Schumacher?
Michael Schumacher's admission that he is currently deriving "no big joy" from his racing as he struggles for the second consecutive year to recapture the magic of former times is leading inevitably to speculation about his future.
The bald facts of his Turkish Grand Prix weekend are just the sort of thing to intensify that speculation.
He was one second off team-mate Nico Rosberg in qualifying. In the race, a clumsy incident with Renault's Vitaly Petrov on the second lap forced Schumacher to pit for a new nose and set the tone for an afternoon that left him 12th, seven places behind Rosberg.
The raw performance deficit to his team-mate is not as great as those numbers make it appear and needs to be seen in context, but some of the race incidents paint a more concerning picture for his future.
The Mercedes WGP-02 car has shown improved pace in the last two races as the team begin to better understand its characteristics, and through Istanbul practice Schumacher's pace was strong, generally within 0.2secs of Rosberg's.
The pair looked set to be vying for a place on the second row and that continued through the first two parts of qualifying.
What happened in the top-10 shoot-out was that Schumacher messed up his one lap and Rosberg did not.
Schumacher took too much speed into Turn One - just as he did in 2006. That pulled him out wide on the exit, he got dust on his tyres and that impacted upon the rest of his lap.
"Looking at the data, we can see Michael had considerably less tyre grip through most of that lap than he'd enjoyed previously," said team principal Ross Brawn.
"It takes a long time for the tyres to recover when you get off line."
That was what was responsible for probably around 80% of the one second chasm between the two Mercedes drivers in their final qualifying times.
Because the team had committed to single-lap runs, that deficit was frozen and goes down in the records.
Yes, it was Schumacher who ran wide and Rosberg who did not, suggesting perhaps that Schumacher's pace was coming with less ease than Rosberg's, but the genuine performance gap between them had they each performed to their potential was in the order of 0.2secs - around half the gap between the Red Bull drivers on the front row, for example.
Schumacher said of his current plight: "What I feel in my hands is the same as it's always felt."
He is no longer claiming that the characteristics of the tyres prevent him from driving naturally.
Unlike last year's Bridgestones, the Pirellis suit him just fine, and in fact with other drivers seem to reward the sort of early direction change that was always a distinctive trait of his style.
The physical sensations and correlation of the driving are now just as they used to be, Schumacher says. And yet...
For the sake of argument let's assume that somewhere in his years away from the wheel he has lost around 0.5secs per lap of raw ability - whether due to the effects of time or the serious neck injury he suffered in a motorbike crash during his retirement from F1.
That's an average of around 0.03secs per corner.
If he is pushing to his own limits in just the way he used to, that much off his former pace will likely feel no different to his on-the-limit laps in his great days.
The speed of the scenery will certainly not look different, the forces acting upon his body will be much the same, the sensations of the car's movements will feel just as they always did.
It will still be sliding around beneath him, he will still be manipulating the weight transfer around the tyres just as he ever did - only not quite as well, to the tune of 0.03secs. It will feel exactly as driving on the limit always did.
A loss of 0.5secs a lap would be enough to transform you from a colossus capable of dominating the sport to a driver 0.2-0.3secs off his team-mate who would struggle to hold down a place in F1 on merit. This might just be where Michael is at.
How he is handling this is only exacerbating his situation.
The Petrov collision in particular looked like the wilful playing out of the frustration of a guy who knows what it is to be the legendary colossus with ability that almost intimidated the opposition aside but is having trouble dealing with the new reality.
That small edge has gone and the opposition don't remember how it was and care even less.
Petrov sailing the Renault down his inside may have been just one ordinary driver not giving him due on-track deference too many.
It started with Toro Rosso's Jaime Alguersuari in Melbourne last year and it has not let up since and into Turn 12 on lap two in Turkey Schumacher just seemed to snap.
The Renault was already well ahead and inside and Schumacher simply turned left into it, front-left against right-rear, trashing his own front wing in the process.
His pace upon rejoining was not too bad, quite comparable to Rosberg's in fact when both were in clear air and at the same stage of tyre life. But there were further clear signs that Schumacher's head wasn't in a place that allowed him to apply his usual savvy racecraft.
The incident where he was trying to fend off Adrian Sutil, made light contact, locked up and let not only Sutil past but also the other Force India of Paul di Resta was particularly illustrative.
There was emotion in Schumacher driving in Turkey - not something that used to be associated with his career. And it was borne of frustration and incomprehension. It's not nice to see.
The qualities that made him the extraordinary competitor he was now seem to be clouding his judgement. Is he even capable of letting himself off the hook he has snagged himself upon?
Mark Hughes has been an F1 journalist for 10 years and is an award-winning author of several books