Summer of George

Is George Kirby a star in the making or should we Kirb our enthusiasm?


During his “Summer of George”, George Constanza, flush with cash thanks to a severance package received upon his firing from the New York Yankees, steadfastly refused to leave his apartment. He lounged around long enough to develop atrophy in his legs. He injured himself playing frisbee golf. George Kirby has spent his own “Summer of George” much more effectively. The much taller, leaner George has pitched to a 7-3 record with a sparkling 2.98 ERA, 1.137 WHIP which comes with a ludicrous 115-14 strikeout to walk ratio. But is the 6’4″ Mariner righty for real? Or should we Kirb our enthusiasm?


Six is Good


Before getting into any pitcher’s underlying metrics, it’s illuminating to understand what they throw. Lots of pitchers come up throwing two, maybe three decent offerings, and that can often lead to short-lived success as the league sees those couple pitches steadily, and knows what’s coming. In Kirby’s case, he throws a veritable smorgasbord of six pitches, and six is good. Do you have a problem with six?

This is where I usually like to display the Baseball Savant pix mitch chart.  It’s colorful and informative, displaying how often a pitcher uses each of his offerings and how that mix has shifted over time. However, Kirby is a rookie and thus there are no elegant, sloping lines to share, just little colored dots that aren’t particularly easy to see. So instead, I have hand-crafted the table below, including Kirby’s pitch mixes and some other relevant data.


It’s No Karl Farbman, But It’ll Do


George Kirby’s Pitches

Two things to note before the delving begins:

First, the Pitcher List page for George Kirby does not list his cutter. It appears to combine his cutter and slider into a single pitch. Also, Kirby began throwing his cutter differently in July which likely accounts for the issue, but there may be some noise amongst the data for the cutter and slider. However, since Baseball Savant does include data for both of those two pitches, I have chosen to include that information in this chart.

Second, negative numbers for movement vs MLB average means that pitch moves less than the average Major League cutter, sinker, etc. A negative number in the run value column means it is good and signals that pitch has been credited with preventing runs.

So there is a lot to like about Kirby’s profile here. He throws his four-seamer most often but still goes to it on less than half his pitches. The heater doesn’t get a ton of drop, but does get better than average x-axis movement, and has been Kirby’s best pitch in terms of CSW (31%) and STR% (74.5). That -15 run value places his four-seamer eighth in the league in preventing runs as well. Kirby’s fastball even produces grounders at a better rate than average. It’s a really effective pitch all around and has been a major driving force during his excellent rookie season.

Kirby’s cutter has been his least effective pitch. He’s allowed a .362 batting average and .638 slugging percentage with it, although its xBA is just .268 and its xSLG just .432. Although his cutter does get hit hard over 40% of the time, which is not good, both of those expected stats are so much better than his actual numbers that helpful regression not only looks likely but has already begun due to his mid-season adjustment.


It…. Moved


His curveball generates above-average movement both vertically and horizontally and has just barely been a plus pitch in terms of run prevention this season. It carries a 29.5 CSW%, which is just slightly under MLB average for curveballs. Kirby has also induced a whopping 60.4% ground ball rate with his hook, which blows away the MLB average of 45.5%. Somewhat strangely, he allows homers at a much higher rate than average when hitters do manage to put his curve in the air. He does throw his curveball in the zone more often than most other pitchers though, which is a consistent trend throughout most of his arsenal. And with that ground ball rate, I’d expect the dingers to slow down too.

The sinker has been really effective for a pitch that gets used less than 10% of the time. Kirby throws it in the strike zone nearly three-quarters of the time, and it has maintained an excellent 29.4 CSW%, although that number is more a result of called strikes than whiffs. He also has allowed a sort of ridiculous 40% Flyball rate when his sinker is put into play, which is way above the average 27%. But on the other hand, zero of those fly balls have turned into dingers, owing in large part to the miniscule 16% HardContact rate allowed on his sinker.

Just like with his curveball, Kirby generates better-than-average movement on both axes with his changeup. Despite that great movement though, his changeup has yielded below-average results. He owns a paltry 18.8 CSW% with it, which is well below the MLB average of 23.4% for changeups and that difference is made up entirely by his inability to generate swinging strikes with it. Batters swing and miss on his off-speed offering just 8.1% of the time.  He allows more than his fair share of line drives with his slow ball, and it gets more than 37% of the time, which is much more often than the league average of 25%.

There is not much of a sample size for Kirby’s slider since he wasn’t throwing one for his first couple months, but it’s been a plus pitch so far and moves a ton. It’s also been unlikely to get hit hard, clocking in with just a 25% HardHit rate.  More importantly, it’s a super encouraging sign to see his effectiveness at implementing an in-season change.


The Airing of Grievances 


There isn’t too much bad to say about George Kirby, but the Airing of Grievances is tradition. His changeup needs work, but that’s a common feature of young pitchers. He doesn’t get enough swings and misses despite the great movement and could maybe benefit from throwing the pitch out of the zone more often, and that’ll perhaps get some hitters to chase. To that end, Kirby could possibly stand to throw a few more pitches out of the zone overall. His Barrel%, Whiff%, and HardHit% all rank among the bottom third of pitchers. These rates coincide with the fact that Kirby has been an absolute control freak, issuing walks at just a 3% rate, which ties him with Aaron Nola for the lowest walk rate in the majors among starting pitchers. This is a strange criticism to be sure, but I actually think Kirby throws too many strikes and could benefit from throwing a few more pitches out of the zone.


Fantasy Takeaway


We’re in mid-September now.  It’s getting chilly, leaves are starting to fall, fantasy football is taking over, and the only people still playing fantasy baseball are likely in the midst of playoff matches or focusing more on next season. With that in mind, Kirby’s next few matchups appear to be @OAK, and then two home starts vs TEX and DET. He beat the Rangers last time he faced them a little over a month ago, going 5.2 innings with five strikeouts and a single free pass. Oakland and Detroit are weak offenses that we’ve probably been streaming against most of the season, so that looks like a very friendly schedule. Kirby looks to be a tremendous asset for the remainder of this season.

Kirby debuted in May this season, (check out Nick Pollack’s in-depth breakdown here) and has only thrown 111.2 innings so far as a result, but he has been ranked inside the top 50 starting pitchers in standard mixed leagues anyway. He will likely garner a few AL Rookie of the Year votes and would have a great chance at taking home the hardware if it weren’t for his uber-talented teammate Julio Rodriguez. With a full season of work next year, I think Kirby could pitch his way into the top 40 or 30 starting pitchers next season, even if he doesn’t improve his secondary pitches. And for the record, I think he will continue to improve his breaking and off-speed offerings, and hopefully keep throwing his new slider more often at the expense of the old cutter. I like him a bit more than his teammate, Logan Gilbert. Both have excellent walk rates and get hit harder than I’d like to see, but Kirby is a bit better in both of those metrics and throws a greater variety of pitches. Not to mention, Kirby can open his mouth wide enough to fully engulf other starting pitchers, and thus gain their abilities (and facial features) for a short amount of time. Pursue Kirby aggressively in dynasty or keeper leagues and draft him as an SP 2 or 3 in the spring.


Featured image by Justin Redler

Sam Lutz

A Pittsburgh native and long suffering Pirate fan, Sam turned to fantasy baseball to give him a reason to follow the sport after July.

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