What Makes a Pitcher’s Count?

What’s a pitcher’s ultimate goal? In the grand scheme, it’s to help win games. A pitcher needs to do his part to keep runs to a minimum — and strikeouts are the best way to accomplish that. Walking, or hitting a better, can’t help. Those outcomes (plus avoiding home runs) are the three rates, each with somewhat separate skills that most of us watch when evaluating pitchers.

And getting ahead in the count is at least partially responsible for all three outcomes. In my first look at pitching ahead to batters I defined a pitcher’s being ahead in the count as having it 0-1, 0-2 or 1-2. Conversely, batters were ahead in 1-0, 2-0, 3-0, 2-1 or 3-1 counts. Those demarcations were made by simply taking the greater number, aside from full counts.

The aggregate numbers support the difference between the two types. In my self-identified pitcher’s counts, batters are held to a .204/.211/.303 line this season. Shifting to a hitter’s count, the batting line more than doubles to .342/.472/.609. Clearly a pitcher benefits when he’s ahead, but I wanted to know about home runs, as well, and whether this was a good division of counts.

I took the 12 possible counts and ordered them by how often a batted ball in that count became a home run. I plotted that alongside the on base percentage (OBP) after reaching that count this season.

hr per swing in count

I used OBP instead of another measurement because I wanted to minimize the effects of home runs in the sorting variable as much as possible. OBP is both easy to find and less susceptible to home runs’ influences than, say, SLG, OPS or wOBA. And if you want to nitpick, yes I had OBP go up to the impossible 1.100 mark. I wanted the vertical axis lines to match up. So, there. Deal with it.

It’s not a surprising result since being behind in the count likely would mean that hitters have to protect more. That can inhibit their ability to square up pitches as they have to cover a much larger space. But, still, it’s nice to see an intuitive piece of baseball faith confirmed with data.

What I was most interested in is how well the two track when compared to each other. There’s a blip where sorting by OBP would have a 1-0 count be more pitcher-friendly than a full count (for obvious reasons), but on the other 10 places, the two numbers agree on the ordinal ranking of the counts.

So, considering the above, should we re-think what a pitcher’s count is? Does 2-2 belong with the more obvious 0-1, 0-2 and 1-2 group? Is 2-1 more of an even count? Do full counts, with their more walks but more strikeouts — and roughly average home run rate — belong in any category?




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Matthew Carruth is a software engineer who has been fascinated with baseball statistics since age five. When not dissecting baseball, he is watching hockey or playing soccer.


12 Responses to “What Makes a Pitcher’s Count?”

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  1. Nathan Nathan says:

    “So, considering the above, should we re-think what a pitcher’s count is? Does 2-2 belong with the more obvious 0-1, 0-2 and 1-2 group? Is 2-1 more of an even count? Do full counts, with their more walks but more strikeouts — and slightly average home run rate — belong in any category?”

    Great question! I’m not sure what a “slightly average home run rate” is, though.

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    • Jack says:

      Literally slightly average home run rate is slightly closer to average than the furthest outlier. For example, if the average number of children people have is 2, and the most anyone has is 50, then having 24 children is slightly average.

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  2. odditie says:

    Why HRs/batted ball? Why not SLG if you want to keep it separate from OBP? Or if you take OBP out of the mix, why not wOBA?

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  3. not being snotty says:

    “Walking, or hitting a better, can’t help. Those outcomes are the three rates, each with somewhat separate skills that most of us watch when evaluating pitchers.”

    I don’t understand this sentence. Maybe you could edit this part of your post or parse it in a comment.

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  4. Monty says:

    If you take out the awkward clause ‘each with somewhat separate skills’, and assume he meant to include home runs somewhere, it reads fine as ‘Those are the three rates most of us watch when evaluating pitchers.’

    Meaning, ‘HRs, BBs, and Ks are the rates most of us watch when evaluating pitchers, and each of them are determined by separate skills.’

    That’s what I got, anyway.

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  5. jfree says:

    I think the counts in the middle (except 3-2) are truly just an irrelevant wash. For those, the advantage goes to whichever player has the best raw talent that day and context isn’t very important. I remember from my own pitching experience which counts made me relax (0-2, 1-2, 2-2, 0-1) and which counts made me tense (2-0, 3-0, 3-1, 3-2). In each of those, there is a big element of “next pitch is important”. And it’s hard to push the context out of your head and pitch without being aware of the context. I suspect that a 3-2 count plays the same game in a batter’s head which is why it ends up more in the middle (ie both batter and pitcher are tense and aware of the context). The 0-1 and 2-0 “next pitch” context is not so much batter specific as it is “Am I controlling this game” (Yes 0-1, No 2-0). Anyway that’s my story and I’m sticking to it.

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  6. Hard at Lunch says:

    I tend to think of 2-2 counts as being in the pitchers favor. A pitcher only needs one pitch to strike you out, but two to walk you. Maybe not very scientific, and it may be more a mental effect than anything, but it changes the way you think about pitch counts. You can extrapolate to other counts as well.

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  7. supgreg says:

    i think it might be easier to figure out by looking at the ratio of fastballs to off-speed pitches in each count. my guess is that hitters counts are that because the fastball is more prominant, while a pitchers count allows for a pitcher to throw any pitch in the arsenal keeping hitters more off balance.

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  8. Todd says:

    2-2 is clearly a pitcher’s count. Immediate danger of a K, but not a BB. The notion that 2-2 is an “even” count is silly. Sure, there’s the same number of strikes and balls, but the maximum number is different, so they’re operating on different scales. 3-2 is an even count, and probably the only really even count aside from 0-0 (though 1-1and 2-1 are close – as shown in your chart). I’ve been baffled by the way baseball people ignore this since I was a kid.

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  9. Justinw303 says:

    I apologize if the answer is right under my nose, but where do you find AB or batted ball outcomes after/during specific counts?

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  10. Kinanik says:

    I wonder how much of this effect is selection bias? The best hitters are going to be pitched around, thus making the average quality of hitter in the ‘hitters’ count’ higher than in the ‘pitchers’ count.’ The worst hitters will be more likely to be in pitchers’ counts. Same logic with pitchers; those with good pitches will be less likely to nibble.

    I don’t doubt that the *ordering* of the counts is correct. But I would guess that the real effect of the count is smaller than the graph above indicates. Of course, isolating each of these effects (an average hitter that gets into better counts will look better than one who doesn’t, so you can’t just regress this onto hitter quality).

    Love articles like this. Thanks!

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  11. Mac says:

    This is a really fun graph to stare at! There’s really a lot going on if you spend some time digging into the numbers.

    Observation 1: Anytime balls outnumber strikes you’re on the right side of 0-0, if strikes are greater than or equal to balls, you’re on the left of 0-0. This makes sense because in a 1-1 count you’re closer to a strikeout (only need three strike pitches) than a walk (needs four ball pitches).

    Observation 2: Try starting at 0-0 and see what happens as a count develops. 0-0 to 0-1? You move left. 0-0 to 1-0? You move right. Now at 0-1, go to 1-1, move right. At 0-1 and go to 0-2, you move left. I believe for every possible count the next ball moves you to the right (better for batter) and the next strike moves you to the left (better for pitcher).

    Observation 2.5: Note that swapping the order of 3-2 and 0-1 doesn’t change observation 2.

    Observation 3: 3-0 is a clear outlier case. I believe this is a result of the well-known baseball philosophy of many hitters always “taking” the 3-0 pitch and not swinging. So you either get the walk or move to 3-1, resulting in an artificially high OBP because fewer hitter attempt to hit.

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