GIF Breakdown: Jack Flaherty’s Fantastic 2018 Debut

Ian Post gives an in-depth look at the arsenal and approach of Cardinals rookie SP Jack Flaherty

(Photo by Tim Spyers/Icon Sportswire)

There’s been a lot of hype within the fantasy baseball community regarding the 22-year-old Cardinals rookie right-hander Jack Flaherty. While his September showing in 2017 was less than desirable (6.33 ERA, 4.62 SIERA, 8.44 K/9, 4.22 BB/9 in 21.1 IP), the numbers he’s posted throughout the minors and even in Spring Training of this year (20 Ks and 5 BBs in 13 IP)  have kept many interested in what Flaherty has to offer. We were all granted a sooner-than-expected look at the young starter thanks to Adam Wainwright injuring a hamstring and opening up a spot in the rotation. My goal is to breakdown everything there was to see, both good and bad, in Jack Flaherty’s 2018 debut on April 3rd in Milwaukee against a potent Brewers lineup. Let’s do this.


Fastball91.0 mph, 50 thrown (55% usage), 10% whiff rate, 6/12 First Pitch Strikes

We’re going to start out with Flaherty’s most glaring flaw – his heater. While the 10% whiff rate isn’t bad, the Fastball as a standalone pitch isn’t much to write home about. It doesn’t blow anyone away as it averages just under 92 mph and the movement is nearly non-existent (very flat) as I honestly couldn’t tell a difference between what’s being labeled a 2-seam and a 4-seam Fastball. Of course, this doesn’t automatically mean it’s destined for failure. If Flaherty can command and mix his pitches effectively, the lack of velocity and movement with the Fastball could be overcome.

Let’s start with one of Jack’s well-placed Fastballs from the Tuesday outing as he dots a 92 mph 1-0 pitch to Lorenzo Cain for a strike on the outside black:

[gfycat data_id=”MediumScaredGrunion”]

To follow that up, let’s take a look at a similar 92 mph Fastball that is once again placed right along the outside corner to Ryan Braun in a 2-1 count:

[gfycat data_id=”AliveAltruisticAnemoneshrimp”]

So far, everything looks great, right? Well let’s change the equation with one small difference and see what happens when Flaherty is asked to hit a similar spot against a left-handed batter. Here we see Yadier Molina asking for an inside Fastball to Christian Yelich on back-to-back pitches. On both attempts, Flaherty almost seems timid to attack and misses towards the middle of the plate – right in Yelich’s wheelhouse:

[gfycat data_id=”DisfiguredPaleEel”]

This was a recurring theme throughout the start. Flaherty had serious difficulty hitting his spots inside to lefties with the Fastball. Later in the game, he would throw nearly an identical mistake pitch, again to Christian Yelich at 90 mph, which was promptly smoked into the outfield for an RBI single:

[gfycat data_id=”VariableShrillAlpineroadguidetigerbeetle”]

There was one lone exception in the outing when Flaherty magically managed to hit his spot on the glove-side black with a lefty in the box. This moment caught the batter, Travis Shaw, completely off guard (as it should have) and seemed to shut his brain off completely:

[gfycat data_id=”PlainVigorousCaterpillar”]

Let’s wrap things up the way we started, on a positive note, with a perfectly placed 92 mph Fastball on the outside corner to Lorenzo Cain for a huge strikeout with runners on in what would be Flaherty’s final frame:

[gfycat data_id=”UnacceptablePlumpDodobird”]


The Fastball from Flaherty isn’t exactly what you’d want ideally from a starter. It doesn’t have plus-velocity, it doesn’t move hardly at all, and Flaherty seems to have issues spotting it on the inside corners to lefties. He did locate it well against right-handed batters, though, and it plays exceptionally well when paired with the Slider. On its own, it’s not much. Where the Fastball gets most its value is how remarkably similar it appears out of the hand, as well as deep in its path to the plate, as Flaherty’s best offering – his Slider.

Slider 82.7 mph, 26 thrown (29% usage), 38.4% whiff rate, 2/4 First Pitch Strikes

The Slider is where Flaherty earns his chops and is by far his best pitch. After earning a swinging strike rate of 28.7% on 81 Sliders thrown in 2017, Flaherty totaled 10 whiffs with just 26 thrown (38.4%) against the Brewers on Tuesday. The offering sat comfortably around 82 mph throughout the entire start and was the go-to pitch when situations were at their most difficult.

Let’s first get a good look at the general movement Flaherty creates with the pitch. The low three-quarter release he has creates a ton of horizontal break. Here we see Brewers catcher Manny Pina flail at an 82 mph Slider in a 1-0 count that’s beautifully placed at the knees on the outside corner:

[gfycat data_id=”LameVictoriousLeopard”]

Now in a 2-2 count against Eric Thames, Jack buries another 82 mph Slide-piece inside that renders an ugly half-hack for the swinging strikeout. I’m really starting to appreciate reactions from Eric Thames – he gives some good ones:

[gfycat data_id=”IllinformedHiddenCaecilian”]

The best thing about Flaherty’s use of the Slider is his ability to go to it confidently when he’s behind or in full counts. He has a propensity to pitch backwards and use the devastating Slider in counts and situations that would typically call for a Fastball. We had an early look at that in the 2nd inning as with nobody out, nobody on, and a full count to Travis Shaw, Flaherty twirled an 82 mph beauty right at the knees for the swinging strikeout:

[gfycat data_id=”BleakConsiderateCowbird”]

I promise this next GIF is different than the last. In what would be a similar situation, with nobody out, a man on, and a full count to Travis Shaw, Flaherty fired an 83 mph Slider right down Broadway for the punchout:

[gfycat data_id=”FrenchDistantGonolek”]

The final Slider GIF perfectly sums up everything there is to love about the pitch. Flaherty is in the toughest spot he’s been in all day with two men on, one out, behind in the count 2-0 to the leadoff hitter Lorenzo Cain, and his pitch count rising in the 5th inning. It’s beginning to look grim for his chances to finish 5 innings and be in line for the Win. So what does he throw? How about a perfectly placed 82 mph Slider that sweeps the entire plate that earns a regrettable whiff:

[gfycat data_id=”SmoothCarefulKronosaurus”]

The Slider from Flaherty is wonderful. It has a ton of break that sweeps across the plate thanks to his low three-quarter release point. It looks nearly identical to the Fastball throughout the delivery, release, tunnel, and majority of it’s path to the plate. Flaherty is confident in throwing it in practically any count or situation – but even better, he can command it effectively at the same time. There weren’t very many errant Sliders throughout the start and if he missed he usually missed down.

Curveball77.3 mph, 14 thrown (15% usage), 0% whiff rate, 3/5 First Pitch Strikes

The Curveball from Flaherty sits right around 77 mph and has some beautiful looping break. It’s almost exclusively used against lefties. I don’t recall him throwing a single Curve to a right-handed batter but I’ll address that later. The 0% whiff rate probably gives away what his intentions are with the pitch – to steal strikes early in counts. Of the 14 Curves thrown, only 2 induced a swing and both of those made contact.

With his 7th pitch of the game, and the first pitch he threw to a LHH, Flaherty executes a perfect 76 mph “get-me-over” Curveball to start ahead in the count to Christian Yelich:

[gfycat data_id=”ElectricIdealBighornedsheep”]

And again in the 2nd inning, in a 1-0 count to Travis Shaw, Jack lands a perfect strike on the outside part of the plate with some sharp break at 77 mph to even the count:

[gfycat data_id=”FearlessEvilGoldfinch”]

And finally, here we get to see back-to-back Curveballs thrown to Eric Thames for a pair of called strikes on the outside corner. Yadier Molina sets up right along the edge and comfortably receives both offerings without having to move his glove much. The head tilting from Thames on the second Curve is probably warranted, but if Flaherty is going to miss, I’d much rather it’s off the plate rather than over it:

[gfycat data_id=”FrayedPlaintiveGarpike”]

The Curveball is a fine piece of the repertoire of Jack Flaherty. It’s a nice change of pace from his more horizontally breaking Slider as it comes in about 5-6 mph slower and with much more vertical action. He’s confident in commanding it within the strikezone and has an ability to use it to work back into counts early on in at-bats. What’s interesting is the fact that Flaherty won’t throw it to RHHs – at all. Add the fact that he failed to record a whiff with the pitch and just 2 of the 14 thrown were swung at and the Curveball becomes something of a novelty pitch that’s limited in it’s use as an effective third offering.


One of my favorite things in baseball and pitching in particular is pitch sequencing. I love getting a grasp for how a pitcher attacks hitters throughout an entire at-bat. Mixing offerings and velocities, changing eye levels, and pitching to both sides of the plate. How does a pitcher’s sequencing change throughout a start and how might he attack righties differently than lefties? You know, that sort of stuff. The good stuff.

First I want to show just how dominant Flaherty’s two-pitch approach to RHHs can be. This first GIF is against the Brewers 8-hole hitter and shortstop, Orlando Arcia. Flaherty starts out with an easy 90 mph Fastball right over the heart of the plate for strike one. You’re at the bottom of the order with a 4-run lead – no need to get cute. What I want you to focus on throughout this entire at-bat is Flaherty’s arm angle and the tunnel he’s creating upon release. They’re all coming from the exact same spot from the view of the hitter. Arcia isn’t being given any indication what’s coming until it’s already too late. The 0-1 Slider shows us just that. Look at the back leg of Arcia completely give out as he waves his bat at nothing but air only to then stare at Flaherty in disbelief. At 0-2, Jack can do whatever he wants. As it turns out, what Jack wants to do is freeze Arcia with a perfectly placed Slider right on the outside black for the strikeout. Gorgeous:

[gfycat data_id=”ThriftyGlassDuck”]

Is it unfair to include at-bats against opposing pitchers? Nah, Chase Anderson’s been in the National League long enough. Fair game. Again, let’s focus on that arm angle and initial path the pitches take out of the hand – they’re all the exact same. Flaherty starts with an easy 91 mph Fastball placed right at the knees and follows that up with another perfectly located heater right (and I mean right) on the outside corner to work an 0-2 count. Also as a side note, this is another example of Jack hitting the glove-side corner to a RHH without a problem. It’s clear to me that it’s only when a LHH is in the box that he struggles to hit that spot. Ok, back to Mr. Anderson. 0-2 count with two Fastballs and Jack decides to rudely throw a sharp looping 81 mph Slider that comes out of the same tunnel as the previous two offerings and records the easy strikeout:

[gfycat data_id=”EasyImmaculateArawana”]

The final GIF of the breakdown is a look at how Flaherty is able to use all three pitches against a lefty and work his way back into a count that he’s behind in. Jack fell behind 2-0 to Christian Yelich in the third inning with a man on. Doing what he loves to do when behind to a lefty, Flaherty dotted a brilliant 76 mph Curveball right on the outside corner at the knees for strike one. Yelich wants nothing to do with that pitch in a 2-0 count and that’s why it’s so effective. When Flaherty can command it, that pitch should be an automatic called strike without a swing almost every time. After working it to 2-1, Flaherty spots a pair of perfectly located Fastballs right on the arm-side black to even the count 2-2. Look at where Yadier Molina sets up and where he receives both these heaters. Excellent command. With Yelich seeing and thinking back-to-back outside Fastballs, Flaherty hits the same tunnel but comes down and in with a wicked 82 mph Slider for the strikeout. Yelich removes his helmet in shame and the inning is over:

 [gfycat data_id=”EnormousWeirdAnnelid”]

The Good

Jack Flaherty shows a ton of promise and upside as a mere 22-year-old within the Cardinals organization. I sometimes have to step back and remember just how young some of these players are when I’m criticizing them as Major League pitchers. He has three legitimate offerings. While the Fastball isn’t what you’d want in your ideal starter, it does play exceptionally well off of his Slider. Other than trying to go inside to lefties, the command Flaherty has with the Fastball is fantastic. That is such an important step for a pitcher to take. Command is often lost amid the desire for velocity but Flaherty certainly has it.

He also mixes his entire repertoire early on in games. There’s no “slow building” of establishing a fastball before using offspeed stuff more often as the game progresses. From the first inning on, hitters have to be ready to hit everything.

The Slider is exceptional. The consistency of his arm angle/release point between his Fastball and Slider are where Flaherty really earns his living. The two pitches sort of buoy each others value because of this. Flaherty struck out 6 Brewers in his first time through the lineup on Tuesday and it was all because of this incredible ability to be deceptive with the Fastball/Slider combination.

Velocity appeared to stay up the entire outing as well. There were a couple times where his Fastball dipped down to 88 mph but he’d recover it in the next at-bat and be back at 92 mph. The Slider stayed right at 82 mph the whole game as well. Consistency isn’t an issue and that’s a plus.

Flaherty also has a good temperament about him on the mound. He doesn’t appear to get too up or too down and stayed collected within himself to execute pitches in tough situations. This is important for pitchers who rely more on command. Whether or not they can stay consistent in their delivery and mechanics in pressure moments with runners on base is crucial.

The Bad

The Fastball is somewhat concerning on it’s own. Sure, as long as it’s commanded well and mixed efficiently with other pitches, it shouldn’t be an issue. My worry is about what happens when the command isn’t there on a given day. A flat 92 mph Fastball is not something you want a pitcher not being able to spot perfectly. Add in that Flaherty has difficulty locating it inside to lefties and there’s cause for future concern. It’s a “what if?” problem that shouldn’t be overlooked.

Regardless of how good the Fastball/Slider combo was on Tuesday, or how good it’s been in the past, I’m worried that Flaherty doesn’t have a third pitch against righties. Going back to my previous point, what happens when one of the two pitches you’re using against righties isn’t working? If he can’t command the Fastball, does he just repeatedly throw Sliders against RHHs? And even worse, what would happen if the Slider isn’t working on a given day? Is Flaherty stuck with a flat 92 mph Fastball to use? Maybe I’m being over-critical (Ian, he’s 22 years old, jeeze, give him a break) but these are things that genuinely need to be worked on. If he’s adamant about not throwing the Curveball to righties, something else needs to develop. Which brings me to my next point.

It appears that Flaherty’s development of a Changeup hasn’t gone well so far. He all but ditched the Change completely in his Tuesday start with just one thrown that was a ball to Eric Thames. I understand that not everyone has to have a Changeup in their arsenal, but with Flaherty’s insistence on sticking with just a Fastball/Slider against RHHs, the Change would be the best possible addition as a third option. Imagine seeing the same arm angle and tunnel as a RHH, and then having to guess whether its going to be straight (Fastball), dive away from you (Slider), or dive into you and under the barrel as a Changeup. A man can dream.

I’ll also play devil’s advocate to the positive point I made that Flaherty mixes in his pitches early and often. While, yes, this is a good thing, it could also be because he simply has to with how ineffective his Fastball is on its own.


Jack Flaherty ultimately lives up to the excitement people had to see him in the rotation in 2018. He’s just 22 years old and already has plus command of 3 pitches. He’s able to utilize both sides of the plate with his Fastball with the exception of inside to lefties. His Slider is plus-plus and a strikeout machine. The confidence Flaherty shows in throwing that Slider in any and all counts creates a headache for opposing hitters who would normally be excited to be sitting at 2-0 against any pitcher. The Curveball is a great tool used to steal strikes from left-handed hitters early on in counts to get ahead and has plenty of differentiation from the Slider as far as velocity and movement.

Flaherty’s best attribute remains being able to disguise both the Fastball and Slider within each other against both righties and lefties with his repeatable arm angle and delivery. The perceived tunnel he creates with this pitch combination has proven to be devastating on hitters and is absolutely the base at which Flaherty finds his success.

The lack of a third offering against righties is concerning, but at 22, Flaherty has plenty of time to toy with a possible solution (please be a Changeup). The other main issue of having trouble hitting his inside spot against lefties is something I’m sure will be worked on throughout his development and is mostly something to keep an eye on as he progresses rather than a major concern.

Overall, we should be thrilled to watch Flaherty grow as a starting pitcher. He has a steady floor already and plenty of extra upside should he develop further as he gets older. After the news of him being sent back down to AAA, I’ll be waiting eagerly like the rest of you for him to be called back up into the Cardinals rotation where he clearly belongs.


Ian Post

Baseball fanatic. Mariner faithful. Former college pitcher who now uses his passion for pitching to break down the arsenal and approach of MLB's newest arms. @IanPostPL on Twitter.

8 responses to “GIF Breakdown: Jack Flaherty’s Fantastic 2018 Debut”

  1. Levi says:

    Excellent breakdown, quality stuff. I appreciate the thorough analysis. It’s articles like this that help me see beyond the numbers and better understand the strategy that goes into every at bat. Thanks!

    • Ian Post says:

      These are my favorite kinds of comments, Levi! Thank you! There’s so much to be learned, in fantasy and otherwise, from simply watching the game that can’t be found in tables and statistics. Glad you enjoyed the piece and thank you for reading.

  2. Michael says:

    I echo Levi, loved this!

  3. Mitch says:

    Excellent piece!! I love how the GIFs are incorporated and explained. It’s one thing peering over stats and reading articles, but nothing compares to seeing footage with it. With all the players to account for, it’s hard for the average joe to get good tape on players. Focusing on a young talent is preferred too, I can carry this Intel for a long time now. Thanks and keep up the good work!! I love this site!!

  4. Big Tuna says:

    Great read. Loved the breakdowns!

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