Around this time last year, Ken Giles fell prey to the right hook… of Ken Giles.

On May 1, while with the Astros, Giles came into a scoreless game against the Yankees. After an Aaron Judge single, Didi Gregorius double, Giancarlo Stanton strikeout, Gary Sanchez homer, and an Aaron Hicks single, Giles exited the game, which, by this point, was no longer scoreless. The Yankees had mounted a four-run lead, and Giles had only recorded a single out. One might say that, as Giles left the field, he was not happy.

That one appearance epitomized Giles’ 2018 tenure with Houston. He pitched to a 4.99 ERA across 30.2 innings, and while his peripherals were very good (a 24% K-rate, a 2% BB-rate), they were still a far cry from where they were at other points during his career. He struggled so heavily during the beginning of that season that he was actually optioned to Triple-A on July 11.

A few weeks later, Houston dealt Giles to the Blue Jays. At the time, Jeff Sullivan referred to the Jays’ acquisition of Giles as them “identif[ing] an opportunity to buy low on a cost-controlled, potentially elite reliever.”

While that Sullivan quote focuses on Giles’ potential, it is important to remember that he had been elite during other points in his career. When he was first brought to the big leagues by the Phillies, he had a sparkling debut. Over his first 115.2 innings, Giles posted a 1.56 ERA with a 33% strikeout rate, and his 100-mph fastball quickly earned him the nickname “100 Miles Giles.”

After parts of two seasons, the Phillies traded Giles to Houston for Vince Velasquez and a few others, including former No. 1 pick Mark Appel. And although the Astros are known for maximizing players’ abilities (Ryan Pressly comes to mind), things seemingly didn’t click between Giles and the organization. A few months after the trade, he offered some criticisms of his time there, telling Rosie DiManno of the Toronto Star in September:

“I’m actually enjoying the game more than I did for my entire tenure in Houston. It’s kind of weird to say that because I won a World Series with that team. But it’s like, I just felt trapped there. I didn’t feel like myself there. Overall, I felt out of place. […] When I came [to Toronto], [the Blue Jays] stayed patient with me. I said hey, I want to work on this thing till I’m comfortable. All right. OK, I’m comfortable, let’s move on to this next thing. Pitching, you can’t just try to fix everything at once. For me, I had to take baby steps to get my groove back. The Jays allowed me to do that. Yeah, the team was out of contention, but it doesn’t matter. It’s still my career. I still have to prove myself. Them being so patient with me, understanding what I want to do, was very, very big.”

The early returns on Giles’ performance in Toronto were not great. The strikeouts ticked up (his K-rate increased by 2.5 points), but the ERA (4.12) remained high with a FIP to match, and home runs became a real issue. All told, Giles’ 2018 was not great, but the Blue Jays still had time to get him right, especially considering that he wouldn’t be a free agent until after next season.

As the title of this article would imply, the Blue Jays have done just that. In 2019, Giles has regained his elite status. Into games on Tuesday, he’s already produced 1.1 WAR, and entering games on Tuesday, that ranked third among all relief pitchers in baseball. He has struck out 40.5% of the batters he has faced, ranking fifth, and he has walked just 6.0%, ranking 33rd. Those two dominant figures, combined with the fact that he has allowed just one home run, have led to a career-best FIP (so far) of 1.27. The ERA is also quite impressive at 1.25, a mark that ranks 10th in the relief pitcher department.

There are two significant changes that may explain Giles’ resurgence in Toronto; I am going to break down both.

The Release Point

Giles’ release point has shifted dramatically. Data from Brooks Baseball tells us that Giles’ release has generally been about the same over his first four-and-a-half seasons in the majors, though it has shifted horizontally at different points in his career. In his short time with the Blue Jays, Giles’ release point has both dropped and moved further from his body.

First, a chart outlining these changes, specifically with a focus on Giles’ fastball, just to get a general idea of what is different:

Ken Giles, Release Point on Fastballs Year Horizontal Release (ft) Vertical Release (ft) 2014 -2.47 6.14 2015 -2.32 6.25 2016 -2.01 6.40 2017 -1.99 6.29 2018 (HOU) -1.91 6.25 2018 (TOR) -2.05 6.21 2019 -2.25 5.99 SOURCE: Brooks Baseball

Now, let’s take a look at Giles in screenshot form, as perhaps this will give us a visual representation of the change he has made. On the left is Giles with the Phillies in 2015, in the center is Giles with the Astros in 2018, and on the right is Giles with the Blue Jays in 2019:

The different camera angles make it tough for me to see the horizontal change, though I would say that Giles’ release does look much further towards the right-handed batter’s box in 2019 than it does in 2018. But I also see a large difference between the 2015 and 2018 Giles horizontal releases, even though there really shouldn’t be one, so that might be a moot point. After all, we’re talking about the difference of inches here, so my own poor timing on the screenshot could come into play. I’m going to trust the numbers here more than my own eye.

The vertical release point change seems to be more stark. Giles has dropped his arm slot slightly (again, we’re talking about three inches here) from last year to this year. That could be partially responsible for the results we are seeing, though I will caveat this by saying that Giles’ pitches, both in terms of velocity and spin rate, are pretty much the same. Perhaps something like this could improve Giles’ command, but even that theory comes back with relatively inconclusive results, as he has always been a pitcher who has done a good job at limiting walks and staying around the zone without pitching into the heart. So while we might have a tangible change here, how it has impacted Giles’ results is relatively unclear and may require a discussion with the pitcher himself. Nonetheless, it remains interesting.

Slider Usage

A more significant change to explore, at least in terms of results, is Giles’ increase in slider usage. Among the 412 pitchers with at least 20 innings pitched this season and 50 innings pitched total between 2018 and 2019, Giles ranks 28th in increased slider usage. That’s the 93rd percentile, an especially interesting figure considering that league-wide slider usage has jumped by 1.4 percentage points from 2018 to 2019.

Giles threw his slider 41% of the time last season according to Pitch Info. That rate is up to 49% this year. That makes sense, considering Giles’ slider has long been his best pitch.

Ken Giles, Slider Results Year wRC+ SwStr% K% wSL Per 100 Pitches 2014 -23 24.9% 60.0% 10.1 3.63 2015 28 25.1% 49.6% 6.4 1.43 2016 -1 34.0% 61.5% 12.7 2.39 2017 5 23.1% 50.8% 11.3 2.51 2018 64 27.2% 42.9% 4.3 1.36 2019 15 27.3% 54.8% 3.6 2.19

What is fascinating here is not Giles’ consistent dominance, but rather his relative struggles with the pitch in 2018. Hitters had literally posted negative wRC+ values against the slider in prior years before producing a less-than-respectable-but-good-comparatively 65 wRC+ against the pitch last year. It’s not that any of the underlying numbers were lacking; batters just managed to square up the pitch for a home run on four separate occasions. Prior to 2018, Giles had allowed just five homers against the pitch. Ever.

That speaks to one of Giles’ chief issues in 2018: allowing hard contact. It wasn’t as if hitters were constantly teeing off against him, despite what the ERA might suggest. His .297 xwOBA last year was still pretty respectable, even if it jumps out as an outlier from his prior seasons. More concerning, however, was Giles’ .381 xwOBA allowed on pitches hitters made contact on, a figure that actually hasn’t come down (.389) here in 2019.

The difference, then, rests in how often hitters are able to make contact against him. In 2018, 70% of swings against Giles resulted in contact, and as that .381 xwOBACON demonstrates, hitters could square him up. This season, Giles’ contact rate has dropped nearly 10 points, to just 61%, a career-best. I don’t mean to over-speculate here, but part of me wonders if this could be due to a combination of the two factors I’ve demonstrated: a new release point might throw hitters off, and an increase in slider usage would result in more whiffs and less contact.

That’s where we’re at with Ken Giles in 2019. He’s come a long way since punching himself in the face about a year ago. While other factors might be coming into play here, Giles appears to have made significant, conscious updates to two aspects of his pitching approach: his release point and his slider usage. With these alterations, he looks like a completely different pitcher, one returning to his elite roots.