Hedging Your Bets on the Nets?

On Monday, Nate Silver looked at the odds of winning a second-round playoff series after going 7 games to win the first round, and found that your chances to win go down:

 Original SRS odds: Miami 88 percent to win the series.
Modified SRS odds: Miami 95 percent to win the series.
Miami swept its opening-round series, while Brooklyn needed seven games to beat the Toronto Raptors. Hence, the Nets have gone from really big underdogs to really, really big underdogs.

Today, FiveThirtyEight writer Benjamin Morris notes that the Nets beat the Heat in all four regular-season games between the two:

Brooklyn mainly has one thing going for it: The team swept its regular-season series against Miami, winning all four games.

Morris plugs this information into a model, and he summarizes his findings:

  • For teams of even strength, the home team is a 66 percent favorite if it was 4-0 against its opponent in the regular season, but a 45 percent underdog if it was 0-4.

  • The shift in odds for a two-game advantage (usually because of a 3-1 or 2-0 head-to-head record) is approximately the same as the value of having home-court advantage for the series(!).

  • While moderately impressive, this gets us nowhere close to making Brooklyn a favorite against Miami by virtue of its 4-0 record alone (though if this were all the information in the world, the 72 percent odds of Miami winning here would be much worse than the 85 percent predicted by the market).

I’ve been a Nets fan since they took University of Maryland teamates Buck Williams and Albert King together in the first round of the 1981 draft, so I hope Morris’s take carries more weight than his boss’s!
And initially, that seems to be the case: Silver estimated their chances of winning dropped about 7% because of going 7 games, while Morris’s finding about the regular-season sweep implies improving their chances by about twice that.
No matter who wins, one of these stories will make it look like these guys really know something!