Thinking About Linear Weights
What is a strike or a ball worth? Especially as a coach? How much of a penalty is it for a hitter to swing at a ball? Or for them to take a strike? I have been thinking about we can better look at hitters on a pitch by pitch basis recently. Wanting to drill down into a more effective way to do this I came across the idea of Linear Weights.
The way I think of Linear Weights at the Pitch by Pitch level is more of a Credit/Debit system. For everything that the player does well he gets “money”, and for every thing that the hitter does that doesn’t help score runs essentially he “owes” money.
After you play with the data you get the following table of values for each event. This is what you gain or lose when you complete the following actions from the offensive end. Along with a few bar graphs to give everyone a visual representation of what these credits and debits look like.
Credits Offense Can Receive
Debits Offense Can Owe
Now if we look at these credits and debits and think about how these can play out in a baseball development system we need to look at what we value. I think it goes without saying that you want to avoid losing value. This can come from a multitude of events but I think that the one that we should focus on is strikes, and swinging strikes.
Both of these events carry a lower negative value than other events that hitters can create. One of the reason these values are lower is the fact that they happen so frequently. Never the less they still carry a lot of negative value over time. The compounding effect of swinging at bad pitches, and taking good pitches can be severe over the course of a season and career.
Just to make things easy lets assume that a player swings at a ball and is now a strike. The value of a ball is equal .05. While (lets round here) a swinging strike is equal -.05. That is a difference of .10. Which doesn’t seem like a big difference.
Lets say a hitter does this 2 times a game for a week of games.
.20 X 7 = 1.40
The value of a home run = 1.39.
Obviously this is a very simplified version, while assuming that he doesn’t gain any value back from taking ball for the most part. The value here can obviously be negated when it comes to different outcomes. But the main point I’m trying to get across is that if we are able to put a value on what a strike and what a ball is worth then it makes those things much more contextual for a player and coaching staff. It is not longer just come vague idea. I think first as coaches we create a common vocabulary, then we create a common value systems. This can only help clarify what we want from players on a daily basis.
Thinking about it economically you start to piece together what a hitter is doing over the course of a season. While also helping to steer them to make better decisions.
