Thursday, May 12, 2016

Joe Ross Breakdown

When I look for pitchers (especially pitching sleepers), I look for guys who do well in 4 areas: racking up strikeouts, avoiding walks, getting groundballs and generating pop-ups. I think of it as "the Holy Quaternity of pitching". I hope to write a full piece about it soon.

The reason they are so important is obvious: strike a batter out, and there's nothing your fielders can do to screw it up; walk a guy, and there's nothing your fielders can do to save you; get a groundball, and you've simultaneously prevented a home run and given yourself a chance at a double play; generate a pop-up, and you've gotten a nearly automatic out and prevented a "productive out" (one that moves or drives in a runner). I obviously look deeper than just these four stats, but they form the foundation from which I work, as well as alerting me when I need to take deeper looks.

Joe Ross has a 2.29 ERA this year. It may surprise you, then, to hear that he's actually gotten worse in each of the four areas I look at. His K% has fallen from 22.0% to 19.0%. His BB% has risen from 6.7% to 7.8%. His groundball rate has fallen from 49.8% to 44.6%. His IFFB% has been cut in two. It's especially concerning to see these changes with Ross because his excellence in these areas is precisely why I targeted him this season.

With his peripherals falling, Ross' ERA has been lowered by .267 BABIP, a 3.1% HR/FB ratio, and an 80.8 LOB%, which have conspired to keep his ERA 1.8 runs lower than his xFIP (4.08). Those numbers are unsustainable. Ross is going to have to improve his peripherals to maintain his fantasy value.

What's driving his peripherals to take a nosedive anyway? Let's start with strikeouts: his swinging strike rate has fallen from an exceptional 11.9% to a merely average 9.3%. Where are the extra swinging strikea going? For one thing, batters are swinging substantially less (48.6% swing rate in 2015, as opposed to only 41.4% thus far in 2016). The swinging strikes don't seem to have disappeared from any one pitch type in particular; both his sinker and slider are getting less whiffs, while his changeup has actually improved (more on this later). So his loss of swinging strikes is coming from a loss of swings more than from giving up more contact. A few sentences ago I asked where the swinging strikes have gone. Now I'm asking a slightly different question: where have the swings gone? While both his Z-Swing% and O-Swing% have tumbled, it's outside the zone that has seen the larger drop. This is not a good sign; it indicates he's fooling less batters.

On occasion, I look at a metric I created and dubbed "Fool%". It attempts to measure the effect a pitcher has on disrupting the hitter's plate discipline. In other words, it looks at how often a pitcher fools a hitter. It's calculation is simple: take the number of pitches thrown inside the zone and not swung at, add the number of swings outside the zone, and divide by total pitches. I haven't done any real research on using "Fool%" as an analytical tool, but I find it nonetheless informative. Joe Ross' Fool% has fallen from 33.7% in 2015 to 30.4% so far in 2016. Needless to say, that's not a good sign.

Like a detective, I'm going to keep asking questions: why is he fooling batters less? Is it something to do with his stuff (losing velocity, moving less), or is it a location issue? Or something else entirely?

According to Pitch F/X, his slider looks almost identical to last year. It's been his most dominant pitch, allowing a .363 OPS. His fastball has lost half a tick, but has gained an inch and a half of arm-side movement. That'a certainly a change, but I'm not sure it's a negative one. As promised earlier on, I will look more at his changeup in a few paragraphs.

His stuff hasn't changed much. Has his location and/or his approach? To examine this question, I present you with a series of heatmaps. In each instance, the heatmap to the right is versus right handed hitters, the heatmap to the left is versus left-handed hitters, and the heatmap in the middle is against all hitters. 2015 is on top, 2016 on bottom. First, the sinker:

The slider:

And the changeup (this one is different: Ross almost never throws it to RHH, so I'm just showing overall heatmaps, 2015 on the left, 2016 on the right):

At risk of boring you with images before I get to my analysis of them, here's one more: a bar graph of his pitch usage by handedness:

Now, with all that data in front of us, we can get a clear look at how Ross is attacking hitters and how that approach has changed, as well as how he's locating.

First, I want to point out the clear pattern in his sinker usage against right-handed hitters: in the 2016 RHH sinker heatmap, you can see three distinct clusters of fastballs, the up and in, up and out, and down and out. When you break it down by batter handedness, you see that he's throwing the pitch inside. His sinker heatmap for this year shows a much clearer plan than it's 2015 counterpart. I also find it interesting how much he seems to use his sinker at the top of the zone, whereas most sinkers are thrown primarily at the bottom. He's using it to freeze hitters, and it's also helped him get pop-ups despite his sinker-slider repertoire.

His plan for his slider doesn't seem to have changed much; he's still throwing it primarily to the glove side corner (away from a RHH, inside to a LHH), though you will notice he's throwing less backdoor sliders to left-handed hitters. His execution of that plan has changed slightly, however. For one thing, he's leaving fewer sliders (and overall pitches, for that matter) in the heart of the zone. His location on that gloveside corner isn't nearly as tightly bunched as it was last year. Whereas 2015's slider heatmap showed the highest concentration exactly on the corner (seriously, look at that), the 2016 version shows his sliders hitting more of a general area, rather than a precise point.

Now, as promised, let's talk about his changeup. There were talks of him adding a splitter this off-season, so I should start by noting that it's possible he's mixing that in as well, but Pitch F/X is registering a changeup only. Anyhow, the talk of an improved changeup was a big reason I heavily targeted Ross during drafts, landing him in all three of my leagues. It seemed to be the missing link for Ross, a weapon to use against left-handed hitters (who were his kryptonite in 2015, slashing .275/.353/.456).

Let's take a look at what a typical Joe Ross changeup looked like in 2015. To do so, I used Pitch F/X to find the most perfectly average changeup thrown by Ross last year (that is, the changeup whose velocity and movement most closely matchup his averages). Here is that pitch:

Now, it's 2016 counterpart:

I'm not really sure what to make of that. The current iteration definitely has less fade, which is normally a bad thing, but perhaps it is a good thing for Ross, creating separation from the arm-side run of his fastball. I think the big change has been location, rather than shape.

If I may now direct your attention once again to the changeup heatmaps as well as the usage graph, I'd like to point out a couple things: First, although he's using his changeup more, he's still throwing it almost exclusively to left handed hitters. He's only thrown it to a right handed hitter 8 times in his entire career. Against LHH, however, he's substantially increased his changeup usage, almost matching his slider. He obviously trusts the pitch much more this year, and for good reason.

Looking at the heatmap, we can clearly see his improved changeup location. He was always throwing it on the outside corner, but now he's also throwing it at the knees more often (obviously a better location for a changeup).

This is really an odd situation. I was really high on Ross pre-season, and he's answered my primary concern by improving the location of his changeup, yet I've found new areas of concern.

Verdict: If you can find a trade partner who thinks Ross has already become the next young ace, you sell. His peripherals show that he's not there yet. If you can't find such a trade partner, you hold on to him. There's immense upside here if he can recapture the dominance of his fastball-slider combination while maintaining the changeup improvements.

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  1. Good stuff but I don't quite understand what all the heat maps are showing, can you explain that?

    1. Actually the pie charts seem a bit too small to understand what the segments mean also.

    2. Heat maps are showing pitch locations, and they're separated by year, and (in the case of the sinker and slider) by batter handedness (LHH on the left, RHH on the right, combined in the middle), with 2015 on top, 2016 on bottom. For the changeup, since he never throws it to RHH, I didn't split by handedness and I put 2015 on the right and 2016 on the left. Does that make sense?

      I'll enlarge the pie charts. Thanks for the feedback.

    3. Actually, the pie charts are already at the largest they can get on Blogspot.

      To zoom in, you will need to open the image (I believe it's an option if you right click on the picture; on an Android, press and hold the image and a menu will pop up with "Open Image" as an option.

      The light blue is the sinker, dark blue/black (can't tell which it is) is the slider and the green is the changeup.

  2. Good stuff but I don't quite understand what all the heat maps are showing, can you explain that?