VALENCIA, SPAIN, NOV 9 - Filippo Preziosi has worked with a number of great riders, but none better than fellow Italian, the legendary Valentino Rossi.Rossi can't talk about the Ducati this year-it was part of the deal with Yamaha to let him test here in Valencia-so it was up to Preziosi, the genius behind Ducati Corse to be his proxy. And it's fair to say that Rossi wouldn't have been as complimentary of himself as Preziosi was after Rossi's first day on the Ducati Desmosedici.The task for Rossi and teammate Nicky Hayden was to choose between the big bang and screamer engines by the end of the two-day test. Rossi had three bikes to test, a 2010 big bang, a 2011 big bang with a revised firing order, and a 2011 screamer engine. The screamer was used from 2007 through 2009, with the change coming this year. Nothing definitive was decided today, but it wasn't for lack of effort or feedback."The most surprising things for me are the way he describes what's happening to the bike, how calm he is," Preziosi said of the nine-time world champion. "That's something I read, but when it happens, it's really strange. His attitude is positive; he found the good things in all the configurations, and he explains why the bad things are not working. That was something I wasn't expecting."More or less, his comments were similar to what we expected. Probably I expected a bit more attention on the negative points, and that surprised me a bit. Normally, a rider will talk about the weak points, because that's where one has to concentrate in order to improve the bike. Valentino, on the other hand, has a 360 degree approach. For every solution, he tells you what the good aspects and the negative aspects are. Probably also knowing the positive aspects helps, because it gives you a more global perspective."Comparing Valentino's feedback to a computer, Preziosi said was "realistic. For example, I asked in what corners the behavior of the screamer was most critical, and the corners that he said were exactly those that we expected they'd be."Rossi spent most of the day working on set-up issues with the GP11 big bang, with one outing on the screamer. He didn't ride the GP10. The team was denied about 2 ½ of track time by a light rain in the morning, which kept everyone off the track until around 12:30 p.m."At the beginning, the problem came from the front on entering; he was unhappy about the grip," Preziosi said. "After that, we solved the problem on the front, and the main issue was on exiting from the corner. But the usual stuff when you're speaking about setup. The most important things we did today is give the right feedback to Valentino and to Jeremy (Burgess, Rossi's crew chief) about what the bike does when you do something, so this, I think, was the most important result of today."What also surprised Preziosi was how Rossi summarized the day. "There's not a summary like, ‘Wow, we're a long ways off, boys. Here we have a lot of work to do,' or anything like that. There's a series of comments, some of which are positive and others negative, about all of the bike's characteristics. Maybe it's because it's the first day, then maybe at the end of the second day, when they close all the doors, maybe later there will be a summarized judgment. But effectively, he knows how to divide things. A thing that normally I suspect is that if there are positive things, they don't get talked about because you concentrate on the negative ones when you have pressure on you, etc. We feel the pressure too, and we want to do well. You might think knowing the things that work well is something that would calm you a bit, like you say, ‘Okay, there are some positive things and some negatives. We can leave it like it is.' No, as long as there's one negative, things aren't okay."