Written by Steve Kennedy, MAA Acquisitions Editor, Knowing vs. Measuring: Doing the Scholarship
appears in the December 2014/January 2015 issue of MAA FOCUS
.

Last winter I participated in the tenure review of a junior
colleague, watched with interest as Miguel Cabrera defeated Mike Trout in a
close American League Most Valuable Player contest, and read a draft version of
Curtis Bennett’s and Jackie Dewar’s
Doingthe Scholarship of Teaching and Learning in Mathematics. It could just have
been the temporal proximity of these experiences that led me to see analogies
between them, but I think there are real connections.
Measuring
First, and most frivolously, the baseball: There is a huge, fascinating, and
contentious debate going on in baseball these days that we might characterize
as traditionalists versus statheads. Even if you are not a baseball fan, you
might know about this from the movie and book
Moneyball.
Baseball players have traditionally been measured by their
batting averages, home runs, and runs batted in. All of these are easy to
count, have obvious meaning, and have value that is clear to even the most
casual baseball fan. All are limited as a measure of what they ostensibly
represent: the player’s contribution to his team winning the game.
For example, batting average is a rough proxy for the
frequency at which a batter gets on base, but it does not count walks, or
reaching base on an error; it values a single and a triple identically; and it
ignores certain outs that achieve other (good) outcomes, such as advancing
another baserunner.
None of these three stats cited even tries to measure
baserunning skill, or the ability to reach base by walk or error, or defensive
prowess.
A number of more advanced statistical measures of a baseball
player’s performance are in use today. WAR, Wins Above Replacement, is one
such. It attempts to measure the total (batting, defensive, baserunning) contribution
of a player to his team’s success.
In 2012 Mike Trout, the young centerfielder for the Los
Angeles Angels, posted a WAR score that was among the two dozen highest in
modern baseball history. That is out of tens of thousands of individual seasons.
In the same season, Miguel Cabrera led the league in all
three of the traditional statistics: batting average, home runs, and runs batted
in. This is, in baseball lingo, called winning the Triple Crown. It had
happened only 15 times previously in baseball history and not since 1967.
Cabrera had a batting season among the best of all time, but he is a slow
runner and not a very good fielder.
WAR (and other advanced statistical metrics that include
baserunning and defense) rated Trout’s season as very strongly more valuable
than Cabrera’s. The debate over the MVP award was widely portrayed as a battle
between crusty, tradition-bound baseball old-timers against basement-dwelling,
smart-aleck nerds.
Essentially the same thing happened in 2013. Cabrera
dominated the old-fashioned offensive categories; Trout lead the league in WAR,
again by a wide margin.