The pattern is actually pretty simple.  With Haywood on the court, we've been about a league-average defensive team.  With him off the court, we're basically at the very bottom.  Assuming, hypothetically, that Haywood played every minute of every game at that same level, our defensive rating would have been good enough for the following respective rankings: 13th, T13th, 15th and 25th.  Without him?  30th, 26th, 30th and T27.  When I speak of Haywood's incredible on/off ratings, this is what I'm talking about.

Of course, it's not all about stats, but they prove the subjective conclusion.  I say that Haywood, due mostly to his size and smarts and not necessarily his effort, is an incredibly underrated defender, particularly on a team with such awful perimeter defenders.  The numbers support that.  Etan Thomas works hard, but he's a poor helpside defender and gives up too much size in individual defense.  He can try all he wants, but he'll never be the defender Haywood is.

Ah, but as you can probably see, there's an outlier here.  Shockingly, it's last season.  For all the talk about Haywood's improvement, he actually affected the defense far less than in past years.  His improvement mostly came on the offensive end, where he became a zillion times more efficient while cutting his turnovers.  Defensively, however, one can make a legitimate argument that he actually got worse.  As you can see, when Haywood was in the game, the Wizards actually defended worse than their season defensive efficiency rating. 

I won't argue that Haywood has dropped off defensively, but I will argue that last year may be the beginning of a trend.  With Randy Ayers coming in, there was much more of an emphasis on team defense than in the past.  This, of course, meant that we protected the paint like crazy, but it also meant that "blame" was spread around more.  This certainly hurt Haywood's impact, and in many ways, it may have been problematic because Haywood is a solid presence that can deter penetration on his own.  It did, however, make things a little easier for everybody else.  Instead of having to remember all these odd zone traps, which can be difficult even for strong defenders, the rest of the Wizards had a true philosophy that their defensive-neglicent minds could actually understand.  Protect the paint, at all costs.

Why does this matter?  Because unlike in past years, where the Wizards' defense was so dependent on Haywood, the club doesn't actually have to change much of their philosophy.  They will still cut off the lane because, for the first time last year, the entire team was doing that instead of Haywood exclusively.  All the drills the team ran during training camp to close out on shooters are still going to make a difference, not only because that's basic defense, but also because they're going to do so from the same areas they did last season.  Essentially, Ayers actually created a scheme, even if one could argue that it was the wrong one because of Haywood's ability to deter penetration on his own.  Now that Haywood is out, that "protect the paint" scheme actually makes sense, and with a year of learning it under their belts, the rest of the club should know better what to do within it.

Of course, another key will be that there are better backup options.  If Etan Thomas returns healthy, he can make up a lot of Haywood's offensive improvement.  He can score pretty efficiently and grab a decent number of offensive boards, though he needs to be less turnover-prone and a better free throw shooter to mimic Haywood.  Andray Blatche's emergence also helps; he proved last year that he can play center, and anything from McGee and Oleksiy Pecherov will be better than past seasons. But the real reason we might be better-equipped to handle Haywood's loss is because of a change in philosophy.

That's not to say the loss stings.  On a team that's likely to play slower with Gilbert Arenas injured, Haywood was an underrated part of the half-court offense, bringing skills no one player can replace.  His loss also means we're going to have to double-team the post even more, opening up shooters on the weakside.  But at the very least, we have more tools to stop the bleeding than we did in 2006/07.