Musings and Rants:
A Rant
First in a series

In football, the statistical term, "turnover ratio," is not a ratio at all.

Webster's Dictionary defines "ratio" as "the indicated quotient of two mathematical quantities." Recalling our lessons in mathematics, a quotient is the result when one mathematical quantity is divided by another. Thus, when we say "the ratio of A to B," we mean the result when quantity A is divided by quantity B.

Now, included among the many reported football statistics is a statistic called "turnover ratio." But a turnover ratio is not a ratio at all! A turnover "ratio" is calculated by subtracting the turnovers a team gives up from the number of turnovers they get. This would be better described as a "difference," or, if you prefer, "differential." Heck, "turnover differential" even sounds cooler than "turnover ratio."

The use of the word "ratio" in "turnover ratio" is not only incorrect, but misleading. To those unschooled in football parlance, a turnover "ratio" of +3 would imply that the team gets 3 turnovers for every 1 turnover they give up. However, a "turnover differential" of +3 would imply that the team has gotten 3 more turnovers than they have given up, which is the intended meaning.

Do the right thing fans of football: say "turnover differential" instead of "turnover ratio."

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Page last updated: 15 June 2003
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