Posted by Neil Paine on May 26, 2009
Well, this past week's games haven't exactly gone according to the numbers, have they? In both of this year's conference finals, we're headed for some pretty serious upsets, at least if you believed the Simple Rating System -- in the East, the Orlando Magic (SRS: 6.49) are really wearing out the Cleveland Cavaliers (8.68), and while the Denver Nuggets (3.13)-vs.-L.A. Lakers (7.11) West finals are technically tied, you can't help but see the Nuggets as the more dominant team in the series right now.
How common is this? I mean, according to SRS, Denver only had an 18.5% probability of winning a 7-game series vs. L.A. without home court advantage, and Orlando's chances were only marginally better at 26.9%. So how many times in the modern (16-team) NBA playoffs have the conference finals produced upsets of this magnitude?
(All probabilities assume a constant 60% home-court advantage.)
|2001||LA Lakers||3.74||San Antonio||7.92||0.165|
As you can see, a Denver win over the Lakers this year would be the 3rd-most improbable conference finals upset since the league expanded to a 16-team playoff bracket in 1984. And an Orlando win (which is looking more and more like a reality with each passing game) would rank as the 5th-biggest upset.
To further heap perspective on what these two teams are attempting to do, a Nuggets win would be, going into the series, approximately as probable as if the Bulls had upset the Pistons in 1989, or if the Nuggets had upset the Lakers (sound familiar?) in 1984. And a Magic win would be an upset on the magnitude of the Knicks upsetting the Pacers in 2000, or the Bulls upsetting the Pistons in 1990 (which they nearly did, pushing the defending champs to 7 games).
But while these are improbable outcomes so far (before the series, the probability of Orlando being up 2-1 on Cleveland after 3 was supposedly 26.1%), upsets like this are not quite as rare as we might think. People love to say "the better team will win a 7-game series," but that's really not always the case. Does the better team usually win? Yes. But over the past 26 years (52 conference finals), you can see that upsets like the kind Orlando and Denver are currently trying to pull off, while rare, are not completely without precedent.
By the way, SRS now says Denver has a 24.5% shot at eventually winning their series with L.A. (most likely in 7 games), and that Orlando has a 53.6% probability of knocking off Cleveland, most likely in 6 games.