The Bulls went into Boston and defeated the Celtics in Game One of their playoffs match-up Saturday.  Many in the sports world are treating this Bulls' win as an upset.  It wasn't.  For the reasons why it wasn't, let's first take a look at some numbers courtesy of John Holinger's article last week:

Celtics' win margin with Kevin Garnett: +9.5
Celtics' win margin without Garnett: +4.0
Celtics' win margin accounting for HCA: +3.4
Bulls' win margin after John Salmons/Brad Miller trade: +2.6

The last two are the keys.  For the whole season the Celtics were the much better team, but in the relevant time period since KG went down and the Bulls made their trade their point differentials are essentially even.  This is a case where the "advanced NBA stats" that I've been pushing this year do a better job of making this clear than the traditional view of just looking at the win-loss record.  There has been much emphasis placed on the fact that the Celtics went 18 - 7 without KG, not a drastically worse win percentage than when he played.  But the difference shows up in the differential, where with KG they tend to blow teams out whereas without him they can still win but in basically toss-up games.  That's what that playoff game was: a toss-up that the Bulls just happened to pull out.  If Pierce makes that free throw in regulation the Celtics win and we aren't even having this conversation, but in a toss-up game anything can happen.  I thought the Cs would win game 1, and I still think they'll win this series.  But without KG this is a lot closer match-up than many would have us believe, and I wouldn't be shocked at all if the Bulls continue to find ways to win.