Walt SAID; "...dial back the power in order to finish and late in the races the Yamahas and Suzukis were as fast as the Ducatis..."
Engine output is simply dialed-in BUT a number of factors influence when it may be appropriate to do so; Engine reliability, tire wear, marketing considerations, rideability, fuel consumption etc. And all of these can be overidden on a case-by-case basis.
Walt and Fret undoubtedly know all this but it is still worth mentioning for folks who might not, and hopefully to stimulate further discussion and learn more.