Friday, June 13, 2014

Running Back Career Yardage Statistics and the NFL Draft.

Running Back Career Yardage Statistics


Question One:  How do average, median, the standard deviation, and the skew of first-choice and second-choice career yards differ?


Data source:  The data used for this problem can be found at





Answer:


Information on career yards rushing for first-choice picks and second-choice picks are presented below.


Descriptive Statistics Career Yards Running
First-Choice Picks
Second-Choice Picks
Diff.
% Diff.
Average Career Yards
6506
5254
1252
10.6%
Median Career Yards
4959
3952
1007
11.3%
Standard Deviation of Career years
4978
4341
637
6.8%
Skew of Career Yards
0.46
1.27
-1
-47.1%



Average career yards rushing and median career yards rushing are a bit more than 10% higher for first-choice picks than for second choice picks.    The standard deviation of first-choice picks is around 7% higher than the standard deviation of second-choice picks.   (I suspect that the slightly higher standard deviation for first-choice picks is largely attributable to a larger number of stellar first-round choices.)

Second round picks are more highly skewed than first round picks.   (The higher skew of second-round choices could be attributable to one outlier, Emmitt Smith. Also, the skew coefficient of 0.46 for first-choice picks suggests a relative modest positive skew.   The distribution for first-choice picks is not far from symmetric.)



My sense is that the difference in performance between first-choice end second choice running backs is relatively small but before I reach firm conclusions I need to look at a much wider range of performance statistics and compare to statistics from other positions.


 #NFL Draft

#Statistics















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