The return of Casey Stoner to Ducati as a test rider has raised more questions than it answered. Fans and media alike are in a state of confusion about his intentions, especially given the times he was setting on the Ducati Desmosedici GP15. What was he doing? Will he race again? When will he test again? To try to put this test and Stoner's role into perspective, here is what we know, what we think we know, and what we don't.

What was Stoner riding?

Casey Stoner spent all three days on the Ducati Desmosedici GP15. He did not test the GP16.

If he's a test rider, why didn't he test the GP16?

A lot of reasons. The GP16 is a brand new bike, and there aren't that many of them yet, so Ducati can't afford to have a test rider destroy one if they crash. The GP16 is not that different to the GP15, so there was plenty for Stoner to test which is transferable to the GP16. Stoner hadn't ridden a MotoGP bike in a year, and hadn't ridden a Ducati since 2010. He hadn't ridden Michelins since 2006, and MotoGP is now using a spec software. For this test, Stoner's aim was to get up to speed, learn and understand the Ducati and a 1000cc era MotoGP bike, complete with Michelins and spec software, and prepare himself for the next test, so that he can provide better input at the next test.

Then, of course, there are the sensitivities of the factory riders. All riders have rather large egos (a prerequisite for convincing yourself that going round in circles faster than others is in some way important), and they could easily see the arrival of Stoner as a threat. Andrea Dovizioso, especially, must have a sense of deja vu, the Italian having lost his seat at Repsol Honda after Stoner switched from Ducati. By giving Stoner the GP15 at the first test, while Dovizioso and Andrea Iannone concentrate on the GP16, the pecking order in the factory is made plain. Ducati cannot afford to upset their factory riders before the season even started.

Casey Stoner was perfectly happy about this situation. "We don't really want to overcomplicate things," Stoner said on Tuesday. "The riders want to do their testing with [the GP16] first. Maybe I'll get an opportunity in the future, but it's better just for me to get accustomed with everything, start to learn a little bit of the progression, and when we find where we want to be with the GP15, not necessarily where the limit is but can feel we can't go too much further, then maybe we will progress to the next version, and see how it works. But there's a lot of time between now and then."

If he wasn't testing the GP16, what was he testing?

After getting a feel for the bike and the tires, Stoner worked on testing major set up changes to try to gauge where the difference was. The purpose of tests like this is to take the bike outside of the safe base developed for the race track, and see if there are any surprises there, and whether the bike behaves as expected. Though the geometry of the GP16 has been changed to suit the Michelin tires, there is still plenty of work on geometry that a test rider can do which is transferable.

Stoner also spent time evaluating front tires for Michelin. Normally, this work is also done by factory riders, but with so much work to do with the new regulations, it is exactly the kind of testing that gets passed off to test riders and sometimes satellite riders. Cal Crutchlow also spent some time evaluating parts for Honda, while the Repsol Honda men focused on electronics and the latest version of the bike.

Stoner's future test program contains similar issues. At some point, Stoner is set to test the Ducati both with and without the winglets, in an attempt to understand the difference between the two. This is important, but is the kind of test work that factory riders are loath to do, as it does not provide immediate improvements. The role of a test rider is gathering the kind of basic data with which to push the direction of development. It is exactly the kind of dirty work which factory riders hate doing.

When is Stoner's next test?

Stoner's next test for Ducati will be a private test at Qatar after the official MotoGP test there.

Really? No Stoner at Phillip Island? Isn't that a missed opportunity?

It's a missed opportunity if you are the Phillip Island circuit, as having the Australian testing there would draw a big crowd to the track, and serve as a great appetizer for the Australian Grand Prix in October.

However, it isn't really a missed opportunity for Ducati. Phillip Island is a very special circuit, but its very nature makes it not well suited as a test track. What Phillip Island tests is the testicular fortitude of the rider, rather than the refinement of a motorcycle. The list of surprising motorcycles which have won there is long, including a Suzuki GSX-R1000 at last year's World Superbike race. "Phillip Island is a special track because you need to be really smooth, make corner speed and have a lot of grip," Maverick Viñales said of testing there. He agreed that the track was more about rider bravery than anything, but as the Suzuki has just had a horsepower boost, it was a good place to test himself as a rider. "I need to use more cojones if I have more power but for sure I have these cojones to use!" he joked.

If Stoner is already setting competitive times on the Ducati, will he be tempted to race?

Stoner himself says not. He said so repeatedly during the test, when asked the question on different days. On Tuesday, his response to being asked if he wanted to be out with the riders during a race was "No. I have no intention of doing that. It's nice to be back on track with them today, mainly to get the data, but I think I'm still going to enjoy standing on the side of the track watching the race rather than being out there." On Wednesday, he repeated that assertion again. "Honestly, I have no plan to race."

Could he change his mind? I don't think you can ever rule it out, but it seems unlikely. Speaking to people who knew him well, they put the chance at very small, but not zero. But there are good reasons to believe that he won't race again: years of racing and crashing have left him battered and bruised, the massive crash at Suzuka only making matters worse. Chatting to Stoner about his physical condition, the Australian mentioned that he couldn't turn his neck to the left properly to look behind him. He also has a recurrent back problem, though that is much better after finding a better therapy to help him with treatment. And earlier this year, he was hospitalized with kidney problems, from which he was thankfully recovered. Like all riders, he has had intimations of mortality. That kind of insight is what takes the ultimate edge off a rider's speed.

If he's not going to race, why is he testing?

Stoner himself answered this best. "My role is completely changed now," he said. "I'm not looking for those fine little details that are out there and comparing things [looking for the ultimate fast lap]. I suppose, I'm not an engineer, but I'm taking the role of an engineer as a test rider. A lot of test riders have careers where they want to achieve things and move forward, but I'm interested in each step, what it does, why it does it. I really want to see this go further forward and take it to another level. So I'm going to start learning all I can from these guys to get a better understanding, because there's a lot of complicated systems."

Would he like to become an engineer in the future? "Probably not a full time engineer, but if I wasn't going to race years ago, something that I wanted to do is get an engineering degree. So it would be nice to learn a lot more from these guys."

Stoner's time away from racing has not made him miss racing, but it has perhaps made him wish to be relevant somehow. Being able to be useful for Ducati, to be listened to and to be able to help them in the right direction, that is what Casey Stoner wants. What he wants, he said, is to be able to give the factory riders the best bike possible, so that they can challenge for the championship with it.

Stoner won on a Ducati which was unrideable. His feedback then didn't make the bike any better. Why would he be of any use now?

There is a common misconception, widely held, that the Ducati got worse because of Casey Stoner's input, and that therefore he is a very poor development rider. While the Ducati did get worse during the period in which Stoner was at Ducati, that had less to do with Stoner, and more to do with the way the racing department worked at Ducati.

Two examples of Stoner's sensitivity and feedback. Cristian Gabarrini once told my friend and fellow journalist Thomas Baujard of Moto Journal that Stoner came into the pits during a test at Qatar and told him that there was something wrong with the engine. Gabarrini looked at the data, and he and the Ducati engineers checked every aspect of the bike and the engine. They could find nothing. So Gabarrini asked Stoner to go out again, and the Australian reluctantly agreed. Halfway round the track on his out lap, the Ducati engine let go, leaving Stoner stranded. It was yet another confirmation for Gabarrini that he needed to trust Stoner's feelings over the data.

The other example came at this test at Sepang. When asked about how the Michelin tires felt, he gave an explanation for why so many riders had crashed in the afternoon of that day. "There's a little point after probably 45°, that it goes down just a little bit more, that it doesn't seem to match with the rear with some of the profiles that we've tested. And that gives everybody a little bit a nervous feeling, and essentially why people are struggling into Turn 5, a big fast open corner, going in, when the bike goes light, it doesn't like that feeling, and it gets the bike a little nervous, and I think that's when the front wants to break away. Everybody has been having a very similar crash there." The crashes were happening either on the way into the corner, or on the way out, both points where the rider is transitioning across that sensitive area. Other riders will just tell you, "it was a strange crash."

The ultimate proof of the error of putting the Ducati's problems down to Casey Stoner came when Valentino Rossi took his place at the Italian factory. Rossi's development credentials are beyond question: his feedback is exceptional ("like a datalogger" crew chief Silvano Galbusera told me), and he has a proven track record of pointing engineers in the right development direction. Ducati listened to Rossi just as much as they had to Stoner, which is to say not very much. Sure, they made lots of changes, but not the changes which were needed.

Ducati's fortunes were reversed with a change in senior management. Since Gigi Dall'Igna took the place vacated by Filippo Preziosi a year earlier, the factory has gone from strength to strength. Dall'Igna has instituted the organizational changes needed to turn the Ducati from also ran to genuine contender. Dall'Igna listens to his riders, and acts on their input. That's the difference.

Riders don't develop bikes, engineers do. But engineers do a better job at developing bikes when they listen to what their riders have to say. Casey Stoner is definitely a rider worth listening to.

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