wOBA Values For Different Pitch Locations

There has been some public work done on how counts, and different outcomes within an at bat change the overall value of a players potential outcome. I think the very best work that has been done on this has been the work done by Masaru Kanemoto in The Theory Of Modern Baseball. After reading the book you realize how much each pitch changes the overall lens of at bat. Strikes in some counts lead to less than ideal or desirable expected values from batters. If you haven’t read the book I highly recommend it as a place to start to think about Counts and At Bats in general.

After reading the book it struck me that you could potentially dig a little big deeper to start to really string out what value hitters can continue to extract. The same way that pitchers have used pitch design to extract value from Data is analogous to how I think we can start to look at players swing decisions in terms of wOBA. I’ve stated in the past that I don’t think that there is a one size fits all approach to handling when and where a players swings or doesn’t swing. But I think that we can gain some guiding principals for hitters to use while building an ‘approach’ that fits them.

The first step in this process to me should is finding out where the value lies, and what counts and swing locations cause outcomes that put hitters in worse positions and not better. I like to think of it like money in some respects. If we are consistently taking on debts, and not adding any value then eventually we will be broke. We really need to figure out how detrimental a bad swing decision can be to a players at bat.

So the first place to start with the information is to look at the wOBA through different counts:

We can see that hitters counts lead to situations where Average wOBA is lower than traditional hitters counts. This is pretty similar to what we find in Theory Of Modern Baseball (TOMB from this point forward). I’m using only 2020 data for this same so there will be slight discrepancies in the outcomes here.

I think that this is a great framework to start with. I think in TOMB we get a clear look at what happens in different at bats. I want to focus in further though and examine a hitters decision to swing or take in different areas of the strike zone. I’m using the a Savant like graphic to illustrate how we will continue:

We are going to take the approach at looking at swings in these three different areas of the plate. Heart of the plate, shadow, and chase area. We can take all three areas and break down what the results are when a player swings or takes in these areas depending on the count. This will give us a really granular way to look at how much a player is adding or subtracting from their (hypothetical) wOBA.

Heart Of The Plate

Before we get into each count let’s look at one count together.

We can see that the table is showing 0–0 counts and we are only using pitches that have been thrown down the heart of the plate. We can see that the average wOBA for pitches in the heart of the plate is .308. If a player is to take a pitch down the area of the plate they would reduce their hypothetical wOBA by 34 points. While they swing they would gain 35 points regardless of the outcome. So in a simplistic way to explain this if a hitter were to swing at every pitch they saw in 0–0 counts their average wOBA would be roughly .343.

Now for the full table. I’ll meet you on the other side what I think are the highlights.

For pitches in the heart of the plate we can see that taking pitches does lead to consistently losing wOBA and in some cases large amounts. We do see larger jumps especially with two strikes (as pitches right down the middle that are with two strikes are often times the end of the at bat). Overall through we can see that swinging does add wOBA in roughly every situation when the pitch is down the middle.

Approach Suggestion

Overall a more aggressive approach should be taken with pitches down the middle of the plate.

Shadow Of The Plate

The shadow of the plate makes this concept show just how close a swing and a take can be on close pitches. We can see that this area of the strike zones is rather confusing hitters. As there seems to be very little difference to swinging or taking at pitches in this area. This is where we may need to examine a players bat to ball abilities and look at whether we can tailor make an approach for them.

The differences in most cases are only a could of points even as counts deepen. Which are normally larger differences because of strike outs. The issue here is that even with the strikeout looming we can see that taking a borderline pitch can sometimes be a ball or strike. This is a really tricky one to examine and should be an area of deeper research.

Approach Suggestion

A more neutral approach should be taken on borderline pitches.

Chase Pitches

This situation shows you the problems with swinging at pitches that are off the plate. We will dig into this and see just how much more effective hitters can be with a patient approach with pitches out of the zone.

Swinging at chase pitches results in a lose of value in almost every count. With extreme loses coming in a few counts. Overall players and coaches need to be aware that there are loses in value when swinging wildly.

Approach Suggestion

Take if possible. Easier said than done, but I the compounding loses that are going to happen over time are difficult to make up.

I don’t think that making adjustments is easy. Hitting is extremely hard. But I think that understanding where and when we are losing value when hitters are at the plate is something that is important. Rather than looking at players and suggesting that they need to make better decisions being able to point to different values and being able to explain why they need to improve their plate discipline should be something that is examined closer.

Thanks for reading.



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