Measuring true team strength
Projecting 2013-14 win totals for the Heat and last season's other outliers
Bill James noted that a baseball team's true strength can generally be measured more accurately by looking at its runs scored and runs allowed rather than its win-loss percentage. That is, he found that one could predict future win-loss percentage more accurately by using the previous season's runs scored and runs allowed rather than the previous season's win-loss percentage.
The same holds true in the NBA: A team's point differential is a better indicator of its true strength than its win-loss percentage. This information can be used to find teams that either greatly underachieved (i.e., had a much lower win-loss percentage than would have been expected based on its point differential) or teams that greatly overachieved (i.e., had a much higher win-loss percentage that would have been expected based on its point differential).
Last Monday, on my "Statitudes" blog, I outlined how to convert a team's point differential into an expected win total. Using that formula, I compared actual wins to expected wins for every NBA team from 1946-47 through 2011-12. In seasons when fewer than 82 games were played, I prorated both wins and expected wins to an 82-game schedule.
For teams that missed their expected win total by at least four games, I made a prediction for the following season:
● If the team won more games than I predicted, they would win fewer games the following season.
● If the team lost more games than I predicted, they would win more games the following season.
Of the 259 teams that missed their expectation by four or more games, 176 (68 percent) matched their prediction the next season, while 83 (32 percent) did not. Considering that no other factors were taken into account -- most notably roster changes -- that's a noteworthy result.
With that in mind, let's take a look at the five NBA teams that missed their expected win total by four or more games in 2012-13 and their prospects for the upcoming season.
Actual: 24 wins | Expected: 28 wins | Difference: minus-4 wins
Cleveland has been one of the busier teams in the offseason, bringing back Mike Brown as head coach, selecting Anthony Bennett with the first overall pick in the draft, and signing Andrew Bynum and Jarrett Jack as free agents. But the key to the Cavaliers' season will once again be Kyrie Irving.