Jake Arrieta’s Sweet… Sinker?
Jake Arrieta’s multi-faceted single-grip slider is sweet, but he’s had that for a while. There has to be something he changed to get better this year. There is something he’s changed, actually. He’s completely flipped his fastball usage.
It’s visually compelling — Arrieta has changed very little about his pitching mix from last year to this year, except when it comes to his fastballs.
Everything stayed the same, he just became a sinkerballer. Even more impressive might be the way that the peripherals on the pitches responded to the change. In 2014, the sinker was for grounders, and the four-seam was for whiffs. As it is for most people. This year? The sinker can do anything it wants.
| Year | Pitch | % Used | X-Mov | Y-Mov | SwStrike% | GB% |
| 2014 | Four-Seam | 20% | -4.0 | 9.6 | 7.7% | 49.1% |
| 2014 | Two-Seam | 28% | -7.0 | 8.4 | 5.3% | 55.0% |
| 2015 | Four-Seam | 8% | -3.5 | 9.1 | 7.0% | 46.2% |
| 2015 | Two-Seam | 43% | -7.3 | 7.6 | 7.4% | 57.9% |
SwStrike% = swinging strike percentage or whiffs/pitches
GB% = ground-ball rate
Now that the two-seamer gets more whiffs and grounders than the four-seam, and is a ball eight percentage points less often than the four-seamer to boot, there’s no real reason to go to the four-seamer that often.
What’s remarkable about the sinker this year is that it’s so similar to the one he used last year. An inch of drop may help the ground-ball rate, and maybe even the whiff rate, but can it explain all of both?
Let’s look at the usage. It looks like he’s using the four-seam primarily for whiffs high in the zone, to the point where he’s not getting a ton of called strikes on a pitch that, by the end of the season, averaged a vertical location that was above the top edge of the strike zone. Take a look at the average location of his four-seamer, it’s almost comical.
So that’s one way that the two-seamer has added some whiffs. It’s become more of his primary fastball, thrown a bit higher in the zone. Maybe there’s more nuance to where he’s throwing the sinker that will uncover more about how Arrieta’s sinker has become useful for both swinging strikes and grounders. Here’s his sinker usage against righties, with last year on the left, and this year on the right.
Last year, Arrieta threw the sinker two ways, it looks like. One approach was to put it on the outside corner for backdoor strikes against righties. The natural arm-side fade of the two-seamer would bring it over the plate for a called strike or a ground ball. The other approach was to throw to their happy zone, low and in, and let the movement take it off the plate for a whiff or a grounder.
This year, Arrieta is just straight blowing it by hitters — or, at least, he’s added throwing the sinker down the middle as a viable approach. One thing that has happened, perhaps as a result, is that he’s getting more called strikes on the outside part of the plate to righties. He’s moved that backdoor pitch closer to the heart of the zone, so it gets more called strikes.
But with whiff and grounder rates up on the sinker, it’s interesting that the middle part of the plate has been the big addition to his portfolio. Let’s look at one last way Arrieta may have changed his sinker usage that may have improved his peripherals. His use of the pitch by count may have changed.
| Count | 2014 | 2015 | % Increase |
| Zero Strikes | 36% | 56% | 56% |
| One Strike | 28% | 42% | 50% |
| Two Strikes | 15% | 27% | 80% |
There we have it. Arrieta is now back-dooring, front-dooring, and suprise-attacking his two-seamer. He’ll throw it so it looks like a strike and then moves into the zone against righties. He’ll throw it so it looks like it’s in the zone and falls out of the zone against lefties and righties. And he’s also throwing the sinker down the middle, at 95, when batters are expecting the curve or the slider.
In other words, Jake Arrieta is now using his two-seamer for called strikes, swinging strikes, and ground balls. So it’s not surprising, maybe, that he’s getting called strikes, swinging strikes, and ground balls on the pitch. Just another great wrinkle from a great pitcher.
With a phone full of pictures of pitchers' fingers, strange beers, and his two toddler sons, Eno Sarris can be found at the ballpark or a brewery most days. Read him here, writing about the A's or Giants at The Athletic, or about beer at October. Follow him on Twitter @enosarris if you can handle the sandwiches and inanity.
Intuitively, throwing the ball down the middle of the zone more shouldn’t make you a better pitcher. I suppose context is everything, and with the slight velocity bump from last year and a little bit of luck variation, it could explain everything. The thing that really stood out to me, though, was how high he’s been throwing his 4-seamers this year. On average, he’s throwing them 5-6 inches higher than last year. I wonder if hitters are queueing up for the high 4-seam fastball and swinging right over the 2-seamer down the middle of the plate.
The other thing that bothers me is that the 2-seamer success is really data source dependent. His pitch f/x stat on fangraphs show a swstr% of 6.0% this year and 5.7% last year. Ground ball rates are similar, too. Could this somehow just be classification related?
His FIP is almost exactly the same as last year. He’s clearly very good and was already, but why the hysteria over ‘how much better’ he is this year?
His second half included a FIP significantly better than anything he’s done before. If you’re willing to put stock in those 100 IP as reflecting something more fundamental, that would explain why the “hysteria” extends even to places like Fangraphs. (Why it exists in non-sabr circles appears obvious.) Would be interested in seeing if Eno’s conclusion was especially true in the second half or if something else (if anything at all) is explaining that difference.
I’m wondering and I could be totally wrong on this but maybe these changes will help him outperform his FIP more often by getting more groundballs and weak contact?
no
Yes
Where did someone bring up the White Sox?
If we’re discussing the White Sox – I believe Chris Sale was top 5 in baseball in “weak contact induced” yet he had a .326 BABIP.
There is still a lot of luck involved in batted balls, whether it’s weak or strong contact. Obviously the slash line with strong contact is much better than weak contact, but there’s no basis to assume a pitcher will outperform his fip because of said “weak contact induced.”
FIP is only one aspect to evaluating a pitcher, not the end all be all. It doesn’t take into account the quality of contact a pitcher can induce which it has been proven elite pitchers can do. There is a reason some pitchers regularly outperform their FIP. FIP is a nice tool but let’s not throw out the other stats/tools we have at our disposal.
He definitely hasn’t improved as drastically as some of the conventional analysts would have you believe. But even if you just look at his peripherals there is evidence that he’s improved since last year.
His strikeout rate has stayed flat at 27%. He’s improved his walk rate from 6.7% to 5.5%. He’s improved his GB/FB ratio from 1.73 to 2.43. His fielding has also improved, as he’s gone from a -3 DRS defender to a +6 DRS defender in 2015.
Besides his HR/FB regressing a bit this year, he’s become a much more complete pitcher in 2015.
The other day I looked at Arietta player page and noticed two things that have led to him being a completely different pitcher in Baltimore.
[1] He’s forgotten how to give up home runs.
[2] His GB% keeps going up.
These are related.
He really forgot how to give up homers … cut his HR/9 in half!
As a Cardinal fan I recognized the relationship immediately as this is the “Dave Duncan Magic” … pound the zone with 2-seamers/sinkers and get them to beat the ball into the ground. No walks, no homers.
He’s approaching 400 IP as a Cub and that seems to me to be enough to state with some confidence that his performance as a Cub should continue (within reason) and he is no longer the same pitcher he was in Baltimore.
For me, the difference is his control. It is at least a full grade better than it was in Baltimore. it allows him to go much deeper into games
Okay, but we know that pitchers do worse the more times they go through the lineup. So, going deeper into games doesn’t necessarily lead to better stats.
He’s been a better pitcher, which allows him to face fewer batters, which lets him pitch deeper into games.
Wrigley Field isn’t exactly known for preventing homers.
Arietta is putting up HR/9 rates that you’d expect from someone pitching in the old Astrodome or Chavez.
His HR rates aren’t sustainable; the difference between a home run and a pop up is a millimeter or less. He’s simply been very lucky in that category.
That’s what I initially thought … but now we are going on 400 IP of “luck”.
I don;t know what the exact # of IP turns it from “luck” to “skill”, but we have to be approaching that number.
I don’t have enough data to look all that far into it, but Pedro’s career HR/FB rate was 8.9% (of the gathered data which sadly does begin just outside his peak).
Kershaw’s HR/FB rate is 7% for his career – pitching in a pitchers park at that. This year, Kershaw’s rate was 10.1%. Did he suddenly forget how to limit home runs?
Arrieta’s rate of 7.8% this year is probably a bit more sustainable than his past two years averaged out. His 80% LOB rate and his BABIP (246) are certainly not sustainable either over an extended period of time. It doesn’t take away from what he accomplished this year, and I think that gets lost to people who take these as personal shots at Arrieta. It just means going forward that he is extremely unlikely to duplicate the results he had this season.
While I agree that HR rate fluctuates wildly, I wouldn’t be so quick to dismiss a guy with a low HR/FB as “lucky”.
Kershaw, for example, is able to generate a ton of pop-ups because of an extremely low Z-Contact%, which has been shown to have a strong negative correlation with pop up rate.
Arrieta is also above average in terms of Z-Contact%, although nowhere near Kershaw’s stratosphere. Given that he’s also a ground-ball pitcher (and ground-ball pitcher’s have higher HR/FB rates), I’d expect for Arrieta’s true talent HR/FB to be around league average.
Baltimore apparently decided that cutters should never be thrown and that pitching mechanics must fit a template. That brilliant organizational philosophy tends to hurt a pitcher with a slider/cutter as a best pitch and mechanics evolving towards a more across-the-body delivery.
But hey, maybe Steve Clevenger turns into a 7 WAR player 😀
Dude don’t be “that” cub fan. There are plenty of sites you can go to and troll. Stick to the content of the article
They haven’t had a chance to troll in a long time. Give them this year.
Steve – you must be new here…
Stop calling us trolls! We are rational, sober, perfectly representative Cubs fans. Look at espn, look at Twitter, look at BP or BBTF — we all write the same way, objectively calling things as we see them, with clinical detachment. Only deranged and meanspirited people (I.e. Cardinals and pirates fans) would characterize our writings as intemperate or delusional (Willy the PhD tells me this is called projection). It is sad that the facts about our baseruns supremacy, impending playoff sweep, and future minimum eight-peat dynasty has unbalanced them so.
By the way, BDC, the Arietta answer is not a perfect game but a one hit 11-0 shutout but he will record 28 strikeouts and hit a home run in the 4th inning.
Just, stop.
Steve, he’s not the problem. You’re the one being “that guy.”
I was watching batting practice a few months ago and got to listen to Arrieta discuss his journey, so to speak. I believe he was talking to a nutritionist, definitely someone on the health/training side of the game that he hadn’t talked to for a long time. It was a pretty interesting conversation going into all of the different things he tried in Baltimore with his mechanics, delivery, and training until one coach(not sure if it was a Cubs coach or someone he worked with in the offseason) told him that everything prior to the release point didn’t really matter. It was all to just get in a good position at the release point and that helped him simplify things and turn his career around. Obviously, he’s still making adjustments and improvements. Amazing run. Really looking forward to the game tonight.
Arrieta’s sinker is so fetch.
Adam, stop trying to make “fetch” happen.
Guess a 11 K, complete game shutout will have to do. Go Cubs Go!