Your 2024 Giants: Kyle Harrison Ace Analysis

Lots of people are doubting on Kyle Harrison, so I thought I would write a post on him.  In particular, a poster of the name Brian M on The Athletic, said that Harrison is no more than a 3-4 starter in baseball, and dismissed the idea that he could be an ace.  

ogc thoughts

I get the doubts about Harrison. People don't have the time to look him up, so they hear about his wildness and assume he's a middle rotation prospect.  Even though he's been named the top LHP pitching prospect two years in a row.  

What I see is a high school draftee who nonetheless turned pro and has dominated to the tune of 13-14 K/9 all the way up the minors, posting pretty good ERAs most of the way up, and then coming to the majors and posting above average numbers:  9.1 K/9, 2.9 BB/9, 3.18 K/BB, 4.15 ERA (NL SP average ERA of 4.56). His main problem (which is huge, no doubt) is homeritis, he just gave up too many homers.

So I thought I would focus one post on investigating him in detail, and discussing what I've seen so far, and documenting all of this. One major thing is that while his seasonal control is high on walks, there are mitigating factors in this that masks his goodness as a pitcher.  

First of all, it is well known in saber circles that pitchers can cover for high walk rates by striking out even more hitters.  I discovered this when looking at Jonathan Sanchez long ago, but you can take any pitcher, and if you add 3 strikeouts and 1 walk to his total, that removes three balls in play, which, given a standard BABIP of .300, means removing one hit, which means that by striking out 3 guys, but giving up 1 walk, you end up removing a hit, while adding a walk, and that's a good exchange because hits can advance and score runners, but walks only pushes runners ahead one base. 

A sign of a good pitcher is a good K/BB ratio that is 2.5+.  Harrison has been above that every season, including MLB, except for his AAA season, which I'll cover below, but the reason that's okay is because his high walk rates is generally caused by wildness early in the season, but by the end of the season, he's managed to reduce the walk rate greatly.  

In AAA, for example, in his first six starts, he was very wild, 12.1 BB/9, but still very high 15.5 K/9, for horrible 1.28 K/BB, but in his next 11 starts (until his injury), he had a 5.1 BB/9, 14.39 K/9, for a good 2.83 K/BB ratio.  That's a bit worrisome since he would be rising up a level, but he reached the majors and not only had a better 3.18 K/BB, he also dropped his walk rate to 2.9 BB/9, which only the best pitchers can do, but most are older and more experienced, he was only 21 YO.

San Jose 2021 Season

Kyle Harrison had a pretty good first pro season in San Jose.  Great 3.19 ERA in 23 games started, but high 4.7 BB/9, but even higher 14.3 K/9 for a good 3.02 K/BB ratio.  Showing his resilience and growth at each level started here, where in his first 6 starts, he had a horrendous 7.5 BB/9 but great 15.5 K/9, for an okay-ish 2.05 K/BB ratio, but in his final 17 starts, he reduced it to 3.9 BB/9 with a still great 14.0 K/9, for an excellent 3.58 K/BB.

Eugene 2022 Season

He had no issues in Eugene, in 7 starts, 1.55 ERA, 3.1 BB/9, astonishing 18.3 K/9 and elite 5.90 K/BB ratio.

Richmond 2022 Season

Again, overall great season in AA, with 3.21 ERA in 18 starts, but high 4.2 BB/9, but higher 13.6 K/9 for a good 3.26 K/BB ratio.  But in his first 5 starts, he had a 4.44 ERA with 5.5 BB/9, 14.4 K/9, and okay 2.60 K/BB, struggling with his higher level.  But in his 13 starts after, he had 2.56 ERA with 3.6 BB/9, 13.3 K/9, and a great 3.67 K/BB, as the pattern continues.

Sacramento 2023 Season

This is his first bad overall season in terms of ERA, with a 4.66 ERA overall, 6.6 BB/9, 14.4 K/9, 2.19 K/BB.  But in terms of his peripherals, it was day and night again, with his first 6 starts being totally wild, with a 14.0 BB/9, 15.5 K/9, and poor 1.29 K/BB, as he reportedly had issues adjusting to the Automatic Balls and Strike automation system, which called balls and strikes.  But in his next 11 starts, before he pulled his hamstring and put himself on the IL, reduced the walks drastically to 5.1 BB/9, plus a still high 14.4 K/9, for a good 2.83 K/BB ratio.  

Giants 2023 Season

And showing that he learned some things in AAA, after he went through his rehab start after his injury, he was promoted to the majors and in 7 starts he had a 4.15 ERA (average NL SP had 4.56 ERA) and a good 2.9 BB/9, good 9.1 K/9, and a good 3.18 K/BB ratio.  

StatCast 2024 Giants Leaderboard

StatCast categorizes pitches thrown by pitchers, and how effective they are relative to norms, and out of 1002 pitches that qualified for the ranking , these were the top 6 Giant pitchers' pitches:

• 4th tie:  Kyle Harrison, +6 run value for his 4-seam fastball
• 4th tie:  Jordan Hicks, +6 run value for his sinker
• 49th tie: Ryan Walker, +3 run value for his slider
• 141st tie: Ryan Walker, +2 run value for his sinker
• 141st tie: Keaton Winn, +2 run value for his slider
• 141st tie: Taylor Rogers, +2 run value for his sweeper

From Maria Guardado's interview with Harrison: 

While Harrison’s fastball has been dominant, his secondary offerings have been far more hittable, with opposing batters going a combined 14-for-31 (.452) with four strikeouts against his changeup, slurve and slider.  

That explains his higher ERA right now, as he's basically only got one effective pitch that he can go to.  He has lost his feel for the slurve, which he used a lot more last season, but is working on finding it back.  And he's is learning how to use his changeup more effectively, which he's using more often this season, and finding it to be a good pitch in his repertoire, getting outs and setting up hitters.  Presumably he'll figure things out in this, his first MLB season, plus he's experiencing a lot of bad ball in play luck so far, as his ERA is 5.00 in 2024, but his xERA, based on the balls in play in StatCast, is only 4.10.

The key thing to me is that Harrison is on the leaderboard (Hicks too!) for most effective pitch in the majors, and he's using it a lot more than other pitchers do (only one pitcher among leaders with more pitches than Harrison's 282, as of April 23, 2024; high usage rate of 68.0%) and yet, despite that high usage rate, hitters still have a hard time seeing the pitch, with a low BA/xBA of .214/.207, low SLG/xSLG of .342/.346, and low wOBA/xwOBA of .264/.260 (where wOBA is mathematically set for average of .300 each season; so hitters are hitting very poorly against this pitch).  

Ted Williams in his book on the Science of Hitting, noted that hitters seeing pitches is a key part of a hitter's routine. He used to take pitches in his first AB in order to get to see more pitches, and would observe the pitches from the dugout and the on-deck circle as well.  The more familiar hitters are with a pitch, the more likely they are to identify it and be able to hit it well.  Harrison, despite using his 4-seamer to a greater degree than most pitchers, has not had this problem so far of hitters identifying this pitch. 

Harrison Has Heat

All of this is why I projected Kyle Harrison to be a future co-ace with Webb atop the rotation. His ability to strike out to an extreme degree so many batters as he rose up the minors (had he stayed in AAA in 2023, he would have led the minors in strikeouts from 2021-23) spoke of his ability to strike out batters easily, a skill that should and has translated to the major.  His ability to learn and adjust at each level, and reduce his walk rate greatly and boost his K/BB ratio into the good range. And now this StatCast factoid now makes it clear that 4-seam fastball is a special pitch.

However, I did not expect that he would have no other secondary pitch to rely upon to get hitters out, that was a huge thing to learn this week. Even last season, his second most effective pitch was his changeup, and xwOBA on that was still a very high .342 (wOBA is scaled to where .300 is considered good).  Thus, he will need to figure out another pitch that will complement his elite 4-seamer and make it even deadlier.

So, overall, he's extremely effective with his 4-seamer, hence why the pitch ranks so high in the major already, but doesn't have a secondary pitch yet, so it looks like he will have an up and down season. Which is not unlike Matt Cain and even Tim Lincecum, in their first full MLB season, which has been something which I've been saying is one scenario of Harrison's development.

With the 4-seamer as the strong foundation of his repertoire, that will buy him the time and experience in the major to work on his other pitches, and figure out the combination that will elevate his performance greatly.  And he has had bad luck so far, as most of the advanced predictors has him performing much better so far this season:  xERA, based on the balls in play in StatCast, is only 4.10, tERA is 3.83, SIERA is 3.84, and xFIP is 4.23.  

And thus it's clear that even with just one (extremely) effective pitch, he's pitching to the above average level of a 4.00 ERA pitcher (where the average NL SP has 4.56 ERA). And once he figures out another pitch, that should push him into the mid-3's ERA. And perhaps adding a third should get him to the 3 ERA region, which is where Webb is.  

And he's only 22 YO this season, so if he spends 2024 figuring out one pitch, that gets him to mid-3's in 2025, at age 23, where he works on and figure out a third pitch, at which point in 2026, at age 24, he'll be co-ace with Webb.  Even if each step takes two seasons instead of one, that gets him to ace level at age 26, which is still young.  He should be advancing to ace level in the 2026-2028 time period, barring injury, and assuming that he can learn another 1-2 pitches in the next few seasons.  With such an effective pitch, I don't see why he can't do it.