Throughout most of the NBA regular season and the beginning of the playoffs, there was very little question in the eyes of NBA experts and observers about which team was the large favorite to win the NBA championship. The Miami Heat were pretty much assured to repeat. With their Game 7 championship victory, the Heat have done nothing to dim the thought of the team as a dynasty and as a team that was significantly better than any competition this year.
Likewise, the Chicago Blackhawks were equally as dominant during the regular season, with 5 less regulation losses than any other team, especially impressive in the shortened NHL season, and were the team that most predicted to win the Stanley Cup.
But just how assured was the championship for these teams?
As the Eastern Conference finals and NBA finals show, the Heat were very close to not repeating. Would losing the finals have been indicative that the Heat were not the super team that they were hyped up to be? Likewise, how likely is a team with as great a regular season as the Blackhawks to win the Stanley Cup? What chance is there that great teams don’t end up winning the championship?
In order to test how often a team of the caliber of the Heat and the Blackhawks actually wins the championship, we can set up a quick simulation. Using the Pythagorean win percentage of each team for the NBA, the normal win percentage for NHL, and the reliable log5 formula used by Bill James, we can simulate individual games and even entire playoff series (where the home team is assigned a weighted advantage). Through this basic simulation, we can see just how likely a team as dominant as the Heat or the Blackhawks during the regular season would fare on average in the playoffs.
This simulation shows that there was only a 31.4% chance that a team like the Heat would have won the championship. In fact, the Thunder were more of a favorite with a 36.2% chance as winning the title (before losing Russell Westbrook to injury of course). Certainly the Heat were not the shoe-ins for the championship that the media had made them out to be.
But because this is a very simple simulation, there are lots of things that it doesn’t account for and there are ways that we can establish a more accurate probability. There are two strong factors that stand out. The most important one is the aforementioned injury to Russell Westbrook, which many argue is the sole reason the Thunder weren’t as competitive as their regular season record may suggest.
The second one, as Nate Silver pointed out, is that the Miami Heat themselves may have not have played to the full extent of their abilities, only applying their greatest effort in very close games or pressure situations. With the playoffs clearly being pressure situations, it wouldn’t be a surprise for the Heat to elevate their game.
We can account for these factors in our simulation by adjusting the pre-log5 rating slightly up for the Heat, and down for the Thunder. This adjustment affects the Heat championship probability a lot, raising it to 56.6%, higher, but still not a sure thing. On average, only slightly more than half the time will a team like the Heat win the NBA Championship. A little less than half the time a team showing similar dominance would not repeat as champions. As good as the Heat were this year, it would have been silly to chalk up a finals loss as due to a lack of dominance. The far better team in a league will very often not win the championship.
We can also see this effect with the Blackhawks who would have only a 40.1% chance at winning the Stanley cup as predicted by their regular season record. They were definitely the favorite, but not a team that would win the Cup more than half the time on average. Again, this is a fairly simple simulation for both of these leagues, but it goes to show the hurdles that multiple rounds of playoffs present, even for a dominant favored team.
Much of the time, really good teams simply won’t win championships purely due to the fact that even though they’re the favorite, they’re not overwhelmingly so. Multiple playoff rounds, all with at least a small chance of failure, add up the odds against one particular team.
So when we do see the rare team that lives up to the hype and is able to repeat, or three-peat, it is even more impressive because it means that they had to be dominant enough not only to be significantly better than other teams, but also good enough to overcome statistical chance.
Georgetown University Class of 2016