I’m writing this blog post with the knowledge that a lot of people reading this, especially those who are “inside” baseball, will be shaking their heads at the monitor once they finish. We're used to dismissing RISP statistics because the sample sizes are too small. In this case, though, we appear to see real and meaningful differences.

Probably the most underappreciated feature on (at least, in terms of clicks per perceived usefulness, to my eyes) is the Pitch Usage table that can be found in the Tabular Data section of each player card. Click it, and you find a fairly detailed breakdown of when a particular pitcher uses what kind of pitch (i.e., pitch percentages split by batter handedness and count).

For example, here’s Ubaldo Jimenez’s Pitch Usage table, from MLB games last season. I’ve added some unsightly orange circles that highlight an interesting trend: Ubaldo tends to throw first-pitch sliders to RHH: is a very active collaboration between myself and Harry Pavlidis; we’re constantly tinkering and adding new features to a shared database and code base. One thing we recently added to our database was baserunner information—i.e., what was the base state of each pitch. So, we added a selector to the Pitch Usage table so that you could look at changes as a function of base runners.

Check out the same trend in Ubaldo’s Pitch Usage with RISP, and you’ll see a fairly dramatic difference:

Now, he’s throwing 64 percent (!) sliders to open ABs to RHH, and only 9 percent four-seam fastballs. Of course, the opposite is true in non-RISP situations (which are also selectable):

You can see slider usage has dropped 30 percentage points, just on the basis of whether there is a runner in scoring position.

We’ve noticed some other interesting trends. For example, R.A. Dickey throws his knuckleball 75-80 percent of the time, even when the batter is ahead, with RISP, but when there’s no RISP, he’s much more likely to throw a two-seam fastball.

Or, Yu Darvish throws a first-pitch four-seam fastball at RHH only 27 percent of the time when there’s a RISP, but uses it 48 percent of the time when there’s no RISP.

I’m sure there are countless other examples. Let me know what you find!

Thank you for reading

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Just wanted to chime in that the pitch usage charts are one of my favorite aspects of the site, and I am stoked to have yet another way to parse the data.

There are so many gems of information to be learned about pitcher tendencies, and one might be surprised at the extent to which some starting pitchers are basically two-pitch guys in many situations, but that the identity of those pitches changes based on the handedeness of the hitter (ie trading sliders vs same-side hitters for change-ups against those with platoon splits). The pitch usage charts put it right there in front of you, allowing the reader to do some (pardon the phrase) advanced-sofa-scouting.
Cool graphs. I think it is well known that pitchers do things like "pitch to the double play" (like throwing low and sinking pitches) in certain situations and also might be more/less likely to challenge pitchers depending on base runner. Someone like Dickey doesn't mind challenging the hitter as much when no one is on, since the effect of a hard hit ball is a lot less.

There is also a potential commingled effect where the quality of hitter could be a little worse with no RISP than with RISP (since the cleanup hitter is up with RISP more than the 9 hitter). So maybe you throw the Dickey fastball to the number 9 hitters of the world while not challenging the cleanup hitters with the potential HR ball.