Charting the 2026 Rookie Pitching Class: Part 1

This crop of rookies has now had some time to get adjusted to the big leagues, and this piece will look to check in on how they have measured up so far through the season. Less of a prediction of things to come, but more so of how much we can rely on them at this stage of their young careers. But of course, this is fantasy. So there will be a natural eye on what could be… are some guys getting the rough end of the stick, and are some getting away with it a little?

Corbin Young recently wrote a fantastic check-in piece that went into depth on some rookie pitchers, Nolan McLean, Parker Messick, and Bubba Chandler. While this won’t go into as much of the nitty-gritty, it is a more macro exercise analysing how they stack up against each other as a whole.

I wanted to establish a composite rating that accounted for metrics that provided a balanced view of their profile as a pitcher, balanced against their xERA. These metrics were then weighted to favor those I felt were more important and those I want to see in a pitcher. This will be split into two pieces: this one sets up the methodology, so to speak, and the reasoning behind the metrics used for the ranking. The next piece will dive into more of the nuances and any interesting cases the data throws up.

It is worth noting how small some of these sample sizes are. I went for qualified pitchers, which included the likes of Gage Jump on just 12 innings and Elmer Rodríguez on 13 innings. I thought about raising the threshold, but there is still value in looking at how these guys are doing, so I offset that with differently sized bubbles to indicate how many innings they have pitched in 2026.

Here are the metrics chosen for the composite z score.

Tier 1

K-BB% – 25% – The ultimate indicator of how well a pitcher is doing. How often are they able to strike out hitters, and how rarely do they issue walks? Swing and miss and keeping hitters off base are foundational for all pitchers and can be struggle points for young pitchers. How well have they made this adjustment from the Minors? SIERA was also an option for this function, but K-BB% just felt cleaner in terms of building a composite rating.

Stuff+ – 25% – Stuff, stuff, stuff, this seems to be the name of the game and is beginning to prove itself as a metric that sticks longer as an indicator. Especially for young pitchers, when they will naturally have blow-up starts against major league hitters, and rough patches will be inevitable, but Stuff+ can kind of look through that and still give us an idea of what these guys have in their locker. Whereas Location+ is a much more volatile game-to-game or month-to-month, and can be easily impacted by variables, whereas Stuff provides a much more stable indicator. Additionally, location can be kind of a non-factor without the stuff, as I referenced Aaron Civale in a previous piece, even with elite Location+ numbers, you will still get hit easily if your stuff is well below average.

Tier 2

CSW% – 20% – This is where I could have gone in any number of directions. Initially, I went with a composite including O-Swing% and O-Contact%. I wanted another way to measure their impact in winning pitches and how well they were able to miss bats. Having played around with it, I ended up swapping it out for Called Strike + Whiff rate; in one metric, it just felt cleaner and had the same role within the ranking.

Z-Contact% – 20% – Limiting contact in the zone can be so critical at the major league level. There is some overlap with Stuff+ and CSW% as it is looking at their movement profile, but it tells a different story — how well a pitcher is able to avoid contact on pitches that hitters do swing at in the zone. Being able to throw strikes and limit contact within the zone can be a real separator.

Tier 3

HardHit% – 10% – Weighted less because of how much it can affect a rating like this, especially over smaller sample sizes, but it is a good indicator of how well they are suppressing hard contact against major league hitters at this stage of the season.

Some other metrics that I considered seriously were ground-ball rate, but this felt too easily impacted by a single start, and in my opinion, shows its true value over a larger sample size. If I do this exercise again at the end of the season, it will be added for sure.

Notes

Hover over the dot to see the player’s name and how they performed in each of the metrics that make up their composite z score.

It is worth noting that the composite z-scores are calculated relative to this rookie class only, not the full MLB qualified starter population — a positive score means above average for this group, not necessarily above average league-wide. This approach was chosen to give clearer visual separation between the pitchers on the chart and to make the comparisons within the class more meaningful than a straight league-wide ranking would allow.

Headline Groupings

These pitchers can loosely be grouped, and this provides a structural framework to dive into in the next piece.

The top right of the chart, Payton Tolle, Logan Henderson, and Trey Yesavage lead the way, with Nolan McLean sneaking into that top grouping but behind the other three, almost a bridge to the next tier.

The next group of five dots provides an interesting mix of very different profiles, with Trevor McDonald, Parker Messick, Connor Prielipp, Walbert Ureña, and Gage Jump off the back of his first two starts.

Then, as we fall below the xERA reference line, we can group Brandon Sproat and Foster Griffin, whose profiles suggest they might have been a little unlucky so far this season. And then some higher-profile names in Bubba Chandler and Connelly Early.

Then the final grouping of those who have struggled even comparatively to other rookie pitchers: Coleman Crow, Noah Schultz, Andrew Painter, Tatsuya Imai, JR Ritchie, Rhett Lowder, and Elmer Rodriguez.

We will look deeper in the second part of this piece, coming early next week.