Losing Poy for the year and relying on Willis - what would that mean?
On the defensive side, losing Poy would mean a lot, but isn't devastating. Poy is clearly the better athlete and defender. Even when Poy disappears, he remains pretty solid on defense. Willis has been playing with more confidence on D and is rebounding better, but isn't in the same class as a determined Poy. The net result if we lose Poy is negative, but the gap is less now than it would have been a month or so ago.
On the offensive side, when factoring in Poy's disappearing acts and inconsistency, and with Willis playing as he has as of late, the net result is a positive for the offense. Willis has a much better handle, makes much quicker decisions, is a good outlet passer and can spread the floor and pull out bigs with his shooting ability. Poy can't do any of these things nearly as well.
The question is, what does this mean for wins and losses? If Poy was more consistent, I would say losing him for the season would be a net negative. But when factoring in his inconsistency, which you have to do, I think we're slightly better with Willis because we know what he'll bring to the floor.
EDIT: I suppose it may make more sense now to compare and contrast Poy with Lee/Humphries.