Since short season ball kicked off, several players in the lower levels of the Astros organization have turned heads with their performance, including catchers Nathan Perry and Nerio Rodriguez, outfielder Yimmi Contabarria and hurler Jairo Lopez. One ballplayer who was stood out in particular is DSL infielder Yohander Martinez, a member of the Astros’ July 2, 2018 haul, who has proven ahead of the pack in summer ball. Martinez, 17, is currently hitting .348/.479/.435 with a jaw-dropping 24/12 BB/K mark through 129 plate appearances, while stealing 12 bases and manning shortstop. His remarkable numbers have made him a hot topic of discussion, with some wondering if it’s time to place him among the organization’s top prospects.
It’s not an unreasonable view- every great career starts somewhere, and minor league statistics are no doubt an informative tool when evaluating players, but the data suggests that if you’re looking for the next big thing, you’re unlikely to find him on a rookie ball stat sheet. When marveling over Yohander Martinez’s gaudy numbers, I decided to take a dive into rookie ball history to find the last Astros farmhand to succeed in the DSL to such a degree. I was mildly surprised by my findings- here’s a ranking of the best wRC+ marks by DSL Astros players since 2006:
With over half of the 2019 campaign in the books, Martinez’s offensive production rates as the best in DSL Astros history, with a comfortable 10 point cushion. However, as you’ve likely noticed, his company isn’t exactly elite. The only player on this list to play in the big leagues is Teoscar Hernandez, whose 2011 performance garnered significant hype due to the power/speed combination he displayed. Many of these players never even reached full season ball. This is not unique to the Astros’ system, either. The leaderboard for all teams looks like this:
Much like the Astros list, there has been very little big league, or even upper minor league, success for the players who qualify here. Obviously, DSL wRC+ is not a strong predictor of future success. In fact, no DSL metric really is. Here’s a ranking by BB/K ratio:
We’re doing a bit better here- Vidal Brujan is a top prospect and Tucupita Marcano is a ranked prospect in the Mariana-deep San Diego farm, but if you were to target players based on their DSL BB/K figures, you obviously would not get very far. In the interest of being thorough, here’s a ranking on ISO:
I’m a big fan of Sherten Apostel, but I don’t find the totality of this list particularly inspiring. At this point, it’s probably apparent that DSL statistics aren’t the best tool in the evaluation toolbox, or at all effective in forecasting future performance. This may not be a huge surprise- the DSL is the most extreme environment in affiliated ball. Fields are small and sparsely attended, much like stateside rookie ball, but the players are even younger, with 17 and 18 year olds being most common and 20 year olds representing elder statesmen. Pitching is seedling green, most players are years away from being physically mature, and defense is rough. A commonly repeated mantra in prospecting is that “development is not linear,” and these DSL leaderboards evidence that.
However, these traits are not unique to DSL statistics. Taking a look into other rookie league leaderboards will tell a similar story. The leaderboard for stateside rookie ball is only marginally better, though most players who have blown away these levels while also being young for them have gone on to some degree of success in the upper minors, at the least:
Hi there, C.J. Abrams. Juan Soto and Joey Gallo also find their ways onto the bottom of this list, with Gallo owning the ISO record and Soto displaying the best combination of age, contact rate and power. It’s worth noting that most of the best lines were fueled by steadfast patience at the dish and, as a result, massive walk rates, demonstrating how green the pitching generally is in rookie ball. The best approach against the 20-40 grade command/control you’re often coming in contact with at these levels is to take a ton of pitches, but the ability to do so obviously isn’t the strongest evidence of major league skills- perhaps it’s best to view rookie ball leaderboards as more of a “feel ranking” than anything else. This leaderboard is also illustrative of the importance of considering age when evaluating minor league performance- of the players in this top 30 who were 21 or older at the time, only Adam Eaton went on to succeed, or even be known as a prospect.
As you move further up the ladder, historical leaderboards feature major leaguers in greater and greater density. Similar pitfalls persist- the vast majority of older “prospects” who have beaten up on the minors in their later 20s have ended up flaming out soon after- but statistical markers do become increasingly predictive. For example, below is the wRC+ leaderboard for all Single-A and High-A seasons from 2006 to present:
The top of this list is no doubt familiar to our readership. Obviously, the hit rate for this list is still rather low, but we see numerous major leaguers in this mix and multiple stars in Martinez and Stanton. When adjusting for age, these success rate starts to look almost okay.
Minor league statistics should always be treated with caution- copious contextualization is necessary to make comparisons between them, and much of what goes into player evaluation either can’t be or hasn’t been captured on a stat sheet to date. It’s not a bad thing to perform at a high level as a teenager in rookie ball- it’s certainly better than struggling- but at the end of the day, your present skills at age 17 aren’t representative of what your skillset will be at 25- and that’s important to remember when you find yourself, starved for any shred of baseball news you can conjure, scratching your neck like a television drug addict, clicking over to the schedule tab on MiLB.com to see what Victor Mascai did in his third at-bat in the middle of your work day.