Monday, May 9, 2011

Playoff Predictability in the NHL and NBA


With the Lakers losing yesterday, the NBA's Western Conference will not have the #1 or #2 seed in their championship series. Quite a surprise, as the NBA playoffs are usually pretty predictable, at least when compared to the Stanley Cup tournament. Or so I thought.

I decided to check if my theory was correct. I took the results from past playoffs, going back eight seasons until 2003, which was when the NBA moved to a 7-game format for the first round. In the 16 conference finals during that time, only once before were both top 2 seeds not represented, that being in the West in 2007 when Dallas was upset by Golden State in the first round and Phoenix lost to the San Antonio in round 2. Overall, 23 out of the 32 top 2 seeds made it to the third round. So at first glance, the NBA playoffs have been reasonably predictable.

To compare, I then took the eight most recent NHL playoff seasons, going back to 2002, as 2005 was skipped due to the lockout. On five occasions a conference championship was contested by two teams that didn't finish in the top 2, most recently last year when #7 Philly beat #8 Montreal in the East. Overall, only 15 out of the 32 top 2 seeds made it to the conference final, which illustrates just how unpredictable the Stanley Cup playoffs have been. Think about it: less than half of the top two teams were able to win two playoff rounds.

For stats geeks, I also did a round-by-round breakdown, counting how many upsets there were for each sport in each round. An upset is simply defined as a lower seed winning the series. Overall, there were 43 upsets out of 120 series (36%) in the NHL compared to just 31 (26%) in the NBA. There was even a bigger disparity in the early rounds. Out of 64 first-round series, 22 were upsets in the NHL (34%) compared to just 12 in the NBA (19%), while in the second round, the upsets were 13/32 (41%) in hockey and just 7/32 (22%) in basketball.

But things changed in the conference finals and championship series. In the NHL, upsets still happened frequently with 7/16 (44%) but in the NBA it was a surprising 10/16 (63%), meaning that it is the third round where the NBA becomes more prone to an upset. In the finals though, the favourite usually wins in both leagues, with only two underdogs taking the NBA title and just one in the NHL.

So generally, the NBA playoffs have been more predictable over the past eight years, which I realize is a very small sample size. But I thought that the predictability meant that the finals were always battles between the top seed in each conference. In fact, out of 16 number 1 seeds since 2003, only 5 made it to the final and only in 2008 (Boston/LA) did both do so. The NHL only saw 3 top seeds win their conference in that time and never had it happen in the same season. So although the NBA follows form early on, it doesn't finish that way.

So what does all this mean and how can it help you? Avoid picking the top seeds to make the Stanley Cup Final for one. Even betting against the top NBA teams wouldn't be as unwise as you might think. But in reality, this just showed me how I let a few results lead me to underestimate the NBA playoffs. It is true that they are not as upset-filled as the NHL, but they are not nearly as predictable as I used to think.

You can argue that the NHL season is meaningless because home advantage is insignificant in the playoffs. Why play 82 games just to gain a 1-game edge? That is true to a point, but generally I think this post demonstrates how the two games differ. First, there is far more parity in the NHL; the NBA usually has 3 or 4 excellent teams which is why the early rounds are more pedestrian. Secondly, a hot goalie (or weak one) can make or break a short series but basketball players rarely play above their capabilities for extended periods. Finally, hockey is a game where hard work can be rewarded, but basketball usually sees talent win out over grit. Simply put, they are completely different sports and you can see this in the way the playoffs develop over two months every year.

Ultimately, doing this simple research led me to appreciate the NBA tournament more than I did. It will never be as interesting to me as the race for Lord Stanley's mug but it is still worth following, because the mantra that makes sports so exciting turns out to be true here as well: You Never Know.

Best,

Sean

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