NBA #1 Seeds that Struggle in the First Round

A post on Hoops Analyst talks about the Los Angeles Lakers - Oklahoma Thunder NBA playoff first round series. The Lakers are the highly rated #1 seed and the Thunder are the lowest rated #8 seed. The two teams are playing a best-of-seven series. The author asks if a #1 seed that is struggling against a #8 seed is "a bad indicator for their success in the playoffs"? The post then looks at each of the #1 seeds that struggled against #8 seeds and concludes "I would venture that there is little correlation between a round one struggle and overall team weakness." What does the data say?


I looked at each #1 seed since 1984--the year the playoffs expanded to 16 teams--and for each #1 seed that won its first round series I looked at how many games, series, and championships the teams went onto win. By comparing the teams that struggled in the first round versus the teams that did not, we can see if first round #1 teams that struggle is a bad indicator for future success. The data supports the author's conclusion. There is little correlation between a round one struggle and a lack of future success in the playoffs. I imported the data into R, ran some regressions, and some t-tests and Wilcox-tests. There was nothing statistically significant between #1 seeds that struggled in the opening round and a lack of future success.


I also made some pivot tables in excel. First is the full data from 1984 to 2009 then the data from 1984 to 2002 and then the data from 2003 to 2009 (in 2003 the first round of the playoffs changed from a best-of-5 to a best-of-7 game series). From 1984 to 2009 teams that did not struggle in the first round, won one more game on average per year than teams that did struggle in the first round. Note that from 1984 to 2002, teams that struggled in the first round went on to win the championship at at a much lesser % (14%) than teams that did not struggle in the first round (45%). From 2003 to 2009 the data does not show anything.