Final Exam jensen_shane-300dpi

Prof. Shane T. Jensen

Please note: This issue’s contest is now closed. 

The answer and Grand Prize winner are posted below. (Feel free, of course, to still test your wits!)

In each issue of Wharton Magazine, we test your knowledge with a question crafted by one of the School’s esteemed faculty members (often straight from an actual Wharton course). Submit the correct answer and you’ll be entered into our drawing for our grand prize—a $400 gift certificate to the Wharton Store. This Final Exam challenge comes from Shane T. Jensen, associate professor of statistics and co-director of the Ph.D. program. Good luck!

Winner of the summer issue Final Exam challenge: George Benz, GED’73, WG’78. Congratulations, George!

The Basics:

The standard metric for evaluating players in hockey is the “plus-minus” statistic. A player’s plus-minus is the total number of goals scored for their team minus the total number of goals scored against their team while that player was on the ice. A problem with plus-minus as a measure of scoring ability, however, is that it does not account for the different quality of line mates or opponents.

The Question:

Consider a particular player with a plus-minus of +40 who plays with very good teammates, and use regression analysis to adjust his plus-minus to account for his four line mates. What is the most reasonable value for his “adjusted plus-minus”?

A. +50

B. +40

C. +30

D. 0

E. -10

The Answer

If this particular player plays with very good teammates, they will serve to give that player a higher plus-minus than he would have otherwise had. Thus, his adjusted plus-minus (accounting for those teammates) will be slightly lower than his observed plus-minus of +40.  So, answer C is the most reasonable choice.  

The Winner:

Out of all correct submissions, one winner will be randomly selected to receive a $400 gift certificate to the Wharton Store. Prize may be subject to taxation; must be 18 years or older to win.

That winner was … Raja Gupta, ENG’96, W’96, WG’07.

Congratulations, Raja!