Dear Sports Fan,
Which baseball stats do we track based on tradition and which really matter?
Thanks for the question. You have put your finger on a question that has come to dominate the conversation among baseball experts – both those who play and coach the game, and those who cover it – for the past decade or more.
More than any other sport baseball values its tradition and measures and compares eras by statistics. In today’s data driven world, however, baseball professionals have come to realize that many of the tools they have relied on are overly blunt.
Common statistics hitters were measured by, for example, included:
- RBI: Runs Batted In – ie, I hit a ball, and as a result a runner already on base scores
- Batting average: the percentage of times a player gets a base hit(successfully reaches base by hitting the ball where it can’t be caught/he can’t be put out)
- ERA: the number of runs a pitcher allows on average (discounting errors by the position players in the field behind him)
- Wins: the number of times a pitcher’s team wins a game when that team maintains a lead established after the pitcher has pitched 5 2/3 innings
What we now know is that these statistics do not actually capture an individual player’s true value – in most cases, because they rely on the contributions or efforts of other players. For example, it’s difficult for a player to have a high RBI count if the players who hit before him don’t get on base – thus giving him an opportunity to drive them home.
In addition, batting average counts hits, but it discounts other contributions a batter makes – for example, getting on base by taking a walk or bunting or hitting a ball in such a way as to move a base-runner ahead, even if they themselves make an out. A pitcher could dominate an opponent and still lose a game because his teammates either do not score runs or play bad defense behind him.
As a result, baseball clubs have largely moved beyond these blunt tools and, to varying degrees of complexity, have designed metrics that directly measure how each individual player’s presence makes it more or less likely for their team to win. This phenomenon – which started in baseball and was captured most memorably in the book Moneyball – has spread to virtually every other sport.
One example of this is the Value Over Replacement Player – an advanced statistic that allows teams to compare one of their players to an an average player at the same position. I basically failed math, so I’d be hard pressed to explain in much more detail – but as far as I can tell, the people who were paying attention in algebra have magically figured out a way to calculate how many more runs a player is contributing to his team than that average player would.
Dean Russell Bell