Is Zach McKinstry a Fantasy Stud?

A closer look at Zach McKinstry's breakout season.

Just a few days before the 2023 season started, the Detroit Tigers traded a 24-year-old organizational depth pitcher in High-A ball, Carlos Guzman, for a backup utility infielder, who would shortly after become one of the Tigers’ best hitters. Now that’s a McKing-sized value. Almost makes up for the ill-advised Javier Báez signing… almost.

On the season, Zach McKinstry is suddenly batting a surprisingly effective .295/.405/.451 with four homers and 10 stolen bases, although much of the heavy lifting for that came in the past two weeks, in which he hit an eye-popping .353/.521/.588 with 2 homers and 5 SB in just 34 AB, with four of the stolen bases all coming this past week. It has led to him getting picked up in many savvier deep leagues and 15-teamers, but he’s still getting overlooked in shallower formats. In ESPN, his roster rate is currently at 6%, up from last week’s rate of below 1%, and it’s currently just 8% in Yahoo, though I expect those to go up by the time you’re reading this.

That’s nice and all, but lots of hitters have had crazy unsustainable surges, especially this year. Christopher Morel belted 9 homers in a handful of weeks. Geraldo Perdomo was hitting .400, and actually is still doing pretty well. Jorge Mateo looked like one of the best hitters in baseball in April before pulling a complete 180 in May. But in the case of McKinstry, I see a player who has truly evolved into a great player, and most people just haven’t noticed yet.

But wait, am I really saying that former journeyman Zach McKinstry, who never had more than 185 PA in a season and never hit over .215, just because he’s coming off a couple hot weeks, could be one of the Tigers’ best hitters? Okay, not really… I’m actually saying that at least at this moment, he is their best hitter. Yes, I know it’s the Tigers, but that’s still a rather bold claim. So let’s look at it!

Zach McKinstry 146 1.7 .379 .403
MLB Rank 18th 27th 22nd 11th

Now, the Tigers have a few other productive or at least currently hot hitters, with his top competition likely coming from former first-rounder Riley Greene, who is hitting .293 with 5 HR and 6 SB this year, and certainly has the brighter long-term projection as a 22-year-old with excellent pedigree. But at this moment, there is no better on the Tigers than Zach Mckinstry, and there aren’t many better players around the league.

His current wRC+ of 146 ranks 18th in all of baseball (minimum 150 PA), just behind Mike Trout and Pete Alonso and just ahead of Lourdes Gurriel Jr. and Jorge Soler. This is despite an ISO of just .156, which is fifty points (.050) lower than the next-lowest ISO of the top 18 hitters. Aside from batting average leader Luis Arraez (Rank: 20th), with his tiny .090 ISO, McKinstry has the lowest ISO out of the Top 30 wRC+ leaders. So, uh, who is this 28-year-old journeyman again?


Zach McKinstry was a former #1 overall pick… wait, that’s not right, I forgot a few decimal places… Zach McKinstry was a former #1001 overall pick, taken as the 25th pick in the 33rd round in the 2016 Amateur Draft by the Los Angeles Dodgers. He had very limited power, never hitting more than three homers at any level, but managed to keep a strikeout rate just under 20% and a double digit walk rate, which was good enough for him to advance up the system, since he was already old for the levels. Then in 2019, he, like many other hitters in both the major and minor leagues, had a big power breakout hitting over .300 with 19 home runs and 8 stolen bases between Double-A and Triple-A.

Although he got a tiny cup of espresso in the majors in 2020, his first real call-up came in 2021, and he made a big initial splash before getting stuck in a cold spell,  getting demoted, and finishing the year with a rather unfortunate .215/.263/.405 line with 7 homers and 1 SB in 172 PA, amounting to a lousy 76 wRC+. Things didn’t go much better in 2022 despite mashing to the tune of .335/.417/.487 in Triple-A, as he hit just .199/.273/.361 with 5 homers and 7 stolen bases after getting traded midseason to the Cubs. This is who he was when he came to Detroit. And then something there really got his motor going.

Essentially, his story is that of a scrappy everyman, well at least in the sense of someone having the incredible level of hand-eye coordination and talent to get drafted by a major league baseball team to begin with. But there are many players around the majors who had a very similar profile, past the age of prospectdom and just on the verge of being useful enough to be a role player on a team but without a carrying tool. Given where he was drafted, just reaching the majors made him a success story. Players like this aren’t supposed to have a higher wRC+ than Mike Trout (143). Yet here we are. But how?

McKontact King

Zach McKinstry Contact Metrics, 2021-2023

Sorry for the data potpourri, but I need it to tell his plate discipline story. And that’s important, since the biggest improvement McKinstry has made to his game, perhaps other than his speed, is his improvements in contact ability and plate discipline. Granted, they’re not as huge improvements as you might expect given the nearly 100-point jump in batting average, but together they all add up. Going from a 30% K% rate to a sub-20% K% vastly improves your chances of MLB success, and so does going from a mediocre walk rate of 6% to an elite walk rate of 16%. From a K/BB standpoint, in two years he went from Ramón Laureano to Mookie Betts. That’s a discipline improvement akin to becoming a Navy SEAL after a year of going to the local bar’s karaoke night and singing “In the Navy” .

You might have noticed that the chase rate, while it improved from 34% to 27%, still didn’t improve enough to justify the walk rate not just doubling but nearly tripling. Usually to get a walk rate like that you need an O-Swing% below 20%, so perhaps regression is warranted. Then again, look at the story his O-Contact% tells. His in-zone contact rate has actually always been good, showing a knack for contact, but it’s been his ability to hit pitches off the plate that’s soared 16% higher over 2 years. While Z-Contact% is usually the more important as it leads to better quality contact, this improved O-Contact% has allowed McKinstry to slap more pitches for hits, but also to foul off more pitches, leading to longer at-bats and more opportunities for walks (and hits).

Contact rate improvement is also important because it is one of the stats to become meaningful the most early, usually reaching the critical point at around 50 PA. That’s because it’s a per-pitch metric as opposed to per-PA, meaning the sample is much larger. So the fact that now he has 150 PA of significantly improved plate skills is unlikely to be a fluke, meaning we have to rethink our idea of him. If he just improved contact and nothing else, it would be enough. But he’s not just improving his quantity of contact, but also the quality.

More Fun Than a Barrel of McKinstrys

Zach McKinstry Batted Ball Quality, 2021-2023

Although the majority of McKinstry’s value has come from his on-base percentage and speed, it’s worth noting that he’s currently rocking a career-best exit velocity and barrel rate. While his new career high MaxEV of 108 mph is still a bit below league average, he’s made up for it with a higher barrel% and hard contact%. The barrel rate is likely to regress some as his current line drive rate of 27% might not be sustainable, but even if it regresses, given his excellent plate skills, even league average power makes him a threat, similar to what we saw with Alex Bregman and early-career Andrew Benintendi (seriously what happened to that guy?).

His groundball rate has steadily decreased, but almost all of that contact has gone into line drive rate, where his flyball rate has stayed steady at his career mark of 37%. Hitting line drives is one of the best things you can do as a hitter for expected outcomes, but it also isn’t very sticky, mostly because consistently hitting line drives is hard to do. But perhaps the way he is achieving this is by hitting to all fields more. Normally you like to see Pull% increase, at least for flyball hitters, since pulled flyballs are ideal for home runs. But McKinstry, who plays in a giant park with lots of outfield space, may have realized a more versatile approach allows for better quality contact, and makes me bullish that he can hold some of these gains.

One more thing for fun… as I mentioned before, having a double-digit barrel rate while also having great contact is rare. Here is a list of the other hitters with a CSW% currently under 24% and a double-digit barrel rate: Bo Bichette, Ronald Acuña Jr., Freddie Freeman, Fernando Tatis Jr., George Springer. One of these hitters is not like the others… and I like it.

Defying all Expectations

McKinstry Expected Stats 2023

Oh, did you want to laugh at my tendency to overreact by saying McKinstry is just a fluke and a hot bat? Well, in that case, BEHOLD! Just look at those beautiful expected stats. Of course, those are descriptive and not predictive, so it’s saying what he deserved thus far, not what he should produce going forward. But it’s especially intriguing in that typically, expected stats tend to underrate speedy players (due to the non-batted ball related impact of sprint speed on BABIP and extra bases for SLG%). And McKinstry definitely brings the speed with his 81st percentile sprint speed.

On the other hand, it does also tend to overrate players who play in bad parks; Spencer Torkelson and Andy Ibáñez are also among hitters with much better expected stats. A few weeks ago, when he seemed to be ice cold, he still had an xBA in the .290 range. So I’d say he’s earned his production thus far. But it’s not just beating expectations by a Detroit 8 Mile, it’s also the trajectory of how he’s achieved this that intrigues me.

McKin Steady Improvements

The thing is, McKinstry has been hot, but this hot streak doesn’t exist in isolation… it’s been the culmination of improvements that have been building nearly all season. Check it out:

McKinstry Rolling Windows: Rolling xwOBA

50PA xwOBA 100PA xWOBA 250PA xWOBA
2023 .457 .429 .366
Δ +.057 +.101 +.102
ΔRank 91st 18th 1st

This may not seem to mean much at first; It clearly shows that his expected wOBA is higher in the most recent small sample than a previous larger sample, and that’s better than the big sample. You could look at that to conclude that most of his success has come more recently, and that wouldn’t be entirely wrong… but here’s the thing. It’s easy to have a hot 50 plate appearances. The mysterious analyst Voros McCracken once theorized a hitter could do virtually anything in 60 PA. But generally, hitters have their little hot streaks, then their little cold streaks. McKinstry hasn’t just kept the heat on, he’s raising the heat and boiling lobsters. Yum!

Although his .457 wOBA in the past 50 PA is among the league’s best, I’m more impressed by the fact that he’s improved his expected wOBA in the past 250 plate appearances more than any other major league hitter. Sure, his overall wOBA over that span isn’t as good as most of the guys behind him (Ronald Acuña Jr. Pete Alonso, Dansby Swanson (though it is a smidge better than #6 improver Riley Greene), but it does suggest that the improvement is legitimate and also implies that while he’s improving the most now, his improvement under the hood has been steady all season, and may have even begun at the end of 2022.

The first new peak comes last season at around PA 325, and returns there at PA 400 before taking off and never looking back.  As Eurovision runner-up Käärijä said regarding his line “It’s crazy. It’s party (for those who added him).”

McKinstreaking Across The Basepaths

I mean, he’s running, don’t worry his clothes are still on, tell Nick to worry. That pun I don’t foresee him being waiver wire fodder for much longer so I have to milk every potential wordplay chance that I can, okay? McKinstry’s main source of fantasy value at this point is his 10 stolen bases, which is good for 18th in the MLB, tied with Myles Straw. It’s rather shocking given that this was never supposed to be a significant part of his game. The most stolen bases he had in any year in the minors was 8, though the 7 he stole last year should have been a hint that something was up. It’s also rather surprising in that he’s done this in only 150 PA (extrapolating to 40 SB over a full 600 PA season), which is considerably less than most of the others on the list who had been regulars since April and have had closer to 200 PA of SB opportunities.

And although this year features some base stealers with mediocre sprint speed, McKinstry’s is actually quite good: his sprint speed of 28.3 ft/s is 86th in the majors, but his time to 1st (better correlated to stolen bases) of 4.28 is tied for 47th and the exact same as speedsters Jon Berti, Travis Jankowski, and fellow stolen base revelation Wander Franco. That’s pretty good company, I’d say. Of course, speed isn’t everything (see Ketel Marte), aggressiveness is, and Zach has both. His 23% SBOT (Stolen Base% per Opportunity) is over double the 10% MLB average, and indicates he’s making the most of his chances on base. Although he’s had fewer plate appearances, it’s somewhat cancelled out by the fact that is OBP is higher than most of the other stolen base leaders, meaning he’s had more stolen base opportunities per plate appearance.

Given the fact that he’s only been caught stealing once, good for a fantastic 91% success rate, there’s no reason for him to slow down. Of course, this will be his first full season, so I wouldn’t be shocked for some fatigue to set in and for him to cool down the aggressiveness now that his starting role is safer. Then again, the Tigers may encourage him to keep the pressure on, and I think 30+ SB is a real possibility. Don’t forget that now he’s entrenched himself as the Tigers’ leadoff hitter, and as someone who can hit for average and draw walks (note I do think the walk rate will regress, but will still be plus), that should mean he’ll continue to get opportunities. That may not matter as much in the major leagues but is fantasy gold for fantasy leagues, especially categories leagues.

Projections and Historical Comps

I’ll start by saying I’m more bullish on McKinstry than most, and not just because I’m a Tigers fan and managed to snag him in most of my leagues, including 12-teamers.  He’s still not rostered in the vast majority of 12-team leagues, and his projections don’t look favorable. TheBatX, a venerated projection system for hitters, projects him to hit just .248/.326/.403 with 4 HR and 5 SB in 179 PA ROS. Which is kind of weird, since they basically project him to returning to a backup role despite also still being projected for a decent 104 wRC+, with his main competitor as Jonathan Schoop. The only projection system that projects him for more than 200 PA is the mysterious ZIPS, and even they only call for .259/.337/.410 with 7 HR and 7 SB in 287 PA. So my conclusions are not exactly consensus opinion.

Usually, you look for comparable players when trying to assess if a player’s so-called breakout is legit, especially since it’s unusual for players to go from terrible to awesome at age 28 without massive power (Max Muncy, Taylor Ward, José Bautista, etc). Who are some other non-pedigree lower-power players in recent memory that had a similar late-career renaissance?

I’m sure there are better names that aren’t coming to mind, but some of the closest that spring to mind are Thairo Estrada, Whit Merrifield, Jon Berti, Josh Rojas, and Ben Zobrist. Yet none of them are perfect matches. Estrada seems to reflect similar power/speed upside and utility defense, yet he lacks the OBP and had his breakout at age 26.  Merrifield may be the closest in terms of age match, though he was had less positional versatility and with significantly worse OBP. Berti was the oldest breakthrough at age 29 and came out of nowhere, but had a groundball rate over 50% capping his power. Rojas has the double-digit OBP with a career year at age 28 with 9 HR and 23 SB, but he did generate more buzz as a minor leaguer with incredible numbers before his initial flop and also has too low a barrel rate and mediocre defense.

I had to dig up a blast from the semi-recent past in Zobrist as a candidate because of the three, he was the only one with an elite walk rate and barrel rate like McKinstry’s 2013, though he also had far more power and did have a strong partial season before the age-28 full breakout in 2018.  Still, it’s encouraging to see that this kind of late-career renaissance has been done before and can be sustainable over a season and even a career. McKinstry has better odds for a safe floor with his high OBP and versatility. But still, McKinstry’s specific profile, notably the crazy one-year improvement and suddenly broad apparent skill base, makes him a unicorn.

Almost Nothing Left to Prove, But There’s Almost Nothing Left

His combination of contact, OBP, moderate pop and speed makes him a near-ideal table-setter, and that should also be good enough to keep him in the leadoff spot. That role is essential for him to score runs but also for his OBP to carry more weight and for him to accrue more SB. But there is one five-ton elephant in the room, one that also is part of why his current plate appearance total is so low, and it rhymes with Splatoon… but it’s not as fun.

Over the course of this season, he only has nine total plate appearances (3 AB) against lefties. That’s nothing! And frankly, it doesn’t seem to make a lot of sense. Sure, in his career, he’s been weaker against lefties, with an 86 wRC+ against them compared to a 101 wRC+ against righties. But he’s a new man now, and he’s done well in his limited lefty matchups in 2023, hitting .333 with a 4/1 K/BB (a 235 wRC+ for lovers of small sample shenanigans). While “platoon-mate” Jonathan Schoop has been fine against lefties with a .306/.390/.389 line against them in 41 PA, that’s not necessarily much better than McKinstry could muster against them, especially when you take into account his superior speed, on-base ability, and (apparently now) power.

I use the quotes on “platoon-mate” because Schoop has a terrible 67 wRC+ without a single homer (granted, Schoop has also been unlucky), and since McKinstry can play all around the diamond, he can always spell other players at different positions of lefty days. It’s at least worth seeing what he can do. Also, there is a chance that within a month the Tigers finally cut their losses and designate Schoop for assignment, as he is in the last year of a rather disastrous two-year deal, and the Tigers and they finally have hope of contending again. Then again, even under new management, I can’t assume the Tigers will do the smart thing, or they know something I don’t.

Also, I don’t want to give short shrift to the guy looking to be the new McKinstry on the block, Zack Short, the 28-year-old who Roster Resource actually currently lists as the Tigers second baseman. He has only 36 PA but has impressed this year with improved plate discipline and a high barrel rate, and also has multi-positional ability. While it might feel like a Zach Spiderman pointing at Zack Spiderman meme, in his case it’s still too early to tell if it’s legit, and given the fact that third base is currently a platoon of Nick Maton and Andy Ibañez, and only McKinstry can also play outfield (and there’s a need for one), he should be fine.

Then again, maybe the Tigers are stubborn or see something I don’t see, like he swings against lefties one-handed or something, and remains a platoon bat all season. In that case, his value does take a hit, which may be less apparent now after facing a long string of righty pitchers. But there are plenty of other players that accrue value despite these limitations… Josh Lowe says hello.

2023 Fantasy Outlook

The times won’t keep being this good for Zach McKinstry, because mathematically, they can’t be. No player has gotten better and better as time has gone on and not regressed at some point, and at some point they’d get stuck at hitting homers in every at-bat, which would surely lead to some people on Reddit complaining that this hitter is absolutely useless for stolen bases.

But what I project going forward is a .260-.270 batting average with a walk rate in the 10-12% range, and just barely reaching double digit total home runs (7-8 home runs ROS) and amassing 20-25 total SB (another 12-17 stolen bases). That takes into account his 2023 improvements while still baking in a fair amount of regression all-around (to not forecast some backslide given his history seemed irresponsible).

Still, that final stat line is essentially not far from what people are raving about with Nico Hoerner (at least in terms of OBP) but with perhaps more power and better versatility. And there is the chance that his xwOBA continues to trend upward or that he simply doesn’t regress, in which case there’s an outside shot at a .290/.400/.450 season line with a total 15 HR and 30 SB, which as a leadoff man would make him a Top 30 fantasy asset, essentially a near-peak Starling Marte with better OBP and more versatility. It’s quite unlikely, sure, but given his peripherals, there is a path to it.

In the end, it’s hard to imagine he’s just a flash in the pan, as the Tigers also need his plus defense at multiple positions. He rates 90th percentile in Outs Above Average, with above average arm strength, which is impressive given the fact he’s played 2B, SS, 3B, LF and RF this year. For fantasy purposes, much like Zobrist, there’s many paths to value, with high average, OBP, barrels and speed, so even if one element gives way, he should still contribute enough in the others to help your team. In most leagues, he’s already triple-eligible with an extremely useful 2B/3B/OF eligibility, with added SS eligibility in some leagues.

The sample size is still rather small, but I think there’s still not enough excitement about just how great he’s been out of nowhere, and how great he can still be going forward. Much like a pitcher who lacks a dominating pitch but succeeds regardless thanks to a wide variety of pitches, McKinstry is the hitters version of this. He should be added in all 15-team formats as well as 12-team OBP formats, but I’d go as far to say to add him as a utility or bench bat even in deeper 10-team OBP, as Zach provides the McKitchen Sink.

Ben Pernick

I've been writing for Pitcher List since the beginning, and have been a fantasy baseball addict now for 20 years. I grew up as a Red Sox fan in New York, but now I declare allegiance only to my fantasy teams.

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