In this paper, we employ machine learning techniques to analyze seventeen
seasons (1999-2000 to 2015-2016) of NBA regular season data from every team to
determine the common characteristics among NBA playoff teams. Each team was
characterized by 26 predictor variables and one binary response variable taking
on a value of "TRUE" if a team had made the playoffs, and value of "FALSE" if a
team had missed the playoffs. After fitting an initial classification tree to
this problem, this tree was then pruned which decreased the test error rate.
Further to this, a random forest of classification trees was grown which
provided a very accurate model from which a variable importance plot was
generated to determine which predictor variables had the greatest influence on
the response variable. The result of this work was the conclusion that the most
important factors in characterizing a team's playoff eligibility are a team's
opponent number of assists per game, a team's opponent number of made two point
shots per game, and a team's number of steals per game. This seems to suggest
that defensive factors as opposed to offensive factors are the most important
characteristics shared among NBA playoff teams. We then use neural networks to
classify championship teams based on regular season data. From this, we show
that the most important factor in a team not winning a championship is that
team's opponent number of made three-point shots per game. This once again
implies that defensive characteristics are of great importance in not only
determining a team's playoff eligibility, but certainly, one can conclude that
a lack of perimeter defense negatively impacts a team's championship chances in
a given season. Further, it is shown that made two-point shots and defensive
rebounding are by far the most important factor in a team's chances at winning
a championship in a given season.