Sporting Charts

Upsets and the NBA Playoffs: Do Lower Seeds Even Have a Chance?

March Madness maybe over, but it doesn’t mean that there’re no more underdogs. The NBA playoffs are just around the corner and with that come a whole new slew of underdogs like the Milwaukee Bucks, Houston Rockets, and the Los Angeles Lakers. Okay, so those may not have the same underdog ring to it as the Florida Gulf Coast University Eagles, but as the lower seeds, these teams are certainly the underdogs of the NBA playoffs.

The NBA Playoffs – The Fairest of All the Playoffs

It’s long been assumed that the NBA has the fairest playoff system, one that more often than not, rewards the better team. In 2002, the NBA moved to a best of seven for each one of their playoff series (previously, after the NBA expanded its playoffs to 16 teams in 1984, the first round was best of five). By doing this, each playoff round in the NBA became equated to about 9% of a regular season, tying them with the NHL (also about 9%) and making the playoffs a closer approximation to a full season than the NFL (6%), baseball (4%), and college basketball (3%).  Over a seven game series in the NBA, the better team has time to adjust to defensive matchups, gimmicky game plans, and general luck.  With all that being said, there have been upsets in the NBA playoffs over the last ten seasons, but they are more rare than any other sport.

This study pulled the numbers from every lower seed in the NBA playoffs over the last ten years (since the NBA shifted to a best of seven first round series). I looked at regular season win percentage, win percentage in the playoffs, and number of playoff series won. Then, I divided up the teams by playoff seed and conference. What I was trying to find was what chance does a lower seed in this year’s NBA playoffs have in pulling an upset? What lower seed, i.e. the 8th seed, 7th seed, 6th seed, and the 5th seed, is more likely to pull said upset? Is there a difference in upset potential between the conferences? And, of course for all those Lakers lovers out there, do the Lakers actually stand a chance as the 7th seed out West? To all of these questions, I found some pretty definitive answers.

East vs. West: What Conference Holds Better Upset Potential?

First of all, not surprisingly, there is a pretty significant split between Eastern and Western lower seeded playoff teams, at least during the regular season. Overall (East and West together), a lower seeded playoff team averaged a .553 win percentage during the regular season, which over an 82 game season translates to about a 45-37 record. When broken down by conference, the Western teams averaged a .589 win percentage (appx. 48-34), while the Eastern teams averaged a .516 win perctenage (appx. 42-40).

When it comes to the playoffs, the gap between the East and West closes slightly. On average, Western teams averaged a .333 win percentage during the playoffs, a record of 89-178, and won 9 playoff series (equating to just a tick over 18% chance of pulling the upset) over the ten-year span.  The East averaged a .327 win percentage, a record of 84-173, and won 7 playoff series (equating to a nearly 15% chance at the upset) over the ten-year span.  The conclusion that you can draw from this is that a typical lower seeded Western team is a good deal better than the typical lower seeded Eastern team during the regular season, but a West team only has a marginal better chance than an East team in pulling a playoff upset.

The 8th Seed – Where Upsets Are Made

If we break down the numbers by seeding, rather than by conferences, we see that a 5th seed, followed by the 6th seed, holds the best chance of pulling an upset; the 5th seed at 25.9% chance and the 6th seed at a 20% clip. This makes logical sense. When it comes to the 7th and 8th seed, it’s reversed. The 8th seed actually holds a better chance at winning a playoff series than a 7th seed. In fact, only one 7th seed has won a playoff series over the last ten years, 2009-2010 San Antonio Spurs. Before the Spurs, the last time a 7th seed pulled the upset on a 2 seed was all the way back during the 97-98 season when the Knicks defeated the Heat. This does not bode well for the current 7th seeders, the Boston Celtics and Los Angeles Lakers.

On the other hand, the 8th seed has pulled an upset three times over the last ten years (equating to 13%), the 2006-2007 Golden State Warriors, the 2010-2011 Memphis Grizzlies, and most recently, the 2011-2012 Philadelphia 76ers (beating the Rose-less #1 seed Bulls). This could mean good news for the current 8th seed in the West, the Houston Rockets.

Upsets Are Hard To Come By

Breaking it down by seeding and conference, we see that the East 5th seed actually holds the best playoff winning percentage at  .413, but the West 5th seed has the best chance of actually winning the series, at 28.6% chance compared to the East 5th seed at a 23.1% chance. As we progress through the lower seeds in each conference, we see the chances at pulling the upset continue to diminish.  To that point, only four Eastern conference teams seeded 6th seed or lower over the last ten years won a playoff series, equating to 13.3% of the time.

Conclusion – Go Chalk

The conclusion we can draw from all of these numbers is that it is extremely hard to even pull the first round upset in the NBA. In fact, crunching all the numbers together, we are left with the lower seeds (no matter seed or conference) holding a 16.7% chance of winning a series. One final nail in the upset coffin: No lower seed since the 1998-1999 #8 seeded New York Knicks (in a lockout-shortened season, no less) has even advanced past the second round (they advanced to the NBA Finals that year). That’s right, no individual lower seeded team has won more than one playoff series in the past 14 seasons.  And to do it, the Knicks needed a four point play in the closing seconds from Grandmama.


So when you are making your NBA playoff predictions this year, chalk is probably the best bet.

 


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