130 at-bats for hitters.
50 innings pitched for pitchers.
Unless you’re a reliever. Then, you need 30 appearances.
Some outlets have restrictions based on age.
Some have restrictions based on service time.
Some just have weird restrictions.
At the end of the day,
What is a Prospect?
To help answer that question, let’s take a look at a few pitchers currently battling it out for the Pittsburgh Pirates’ 2021 rotation.
First up, we have Mitch Keller.
Keller isn’t eligible as a prospect, due to already having pitched 69.2 innings in the majors across two seasons. He lost his prospect eligibility in 2020, after ending the 2019 season with 48 innings — two shy of the standard limit. This will be Keller’s age 25 season, and no one really knows for sure what to expect this year. I’m still projecting him to be a middle of the rotation starter or better, with a good chance at top of the rotation upside.
Next, let’s go to JT Brubaker.
Brubaker is eligible as a prospect by the innings standard, with only 47.1 innings under his belt. While Keller has about 22 innings more than Brubaker — which amounts to Keller’s entire 2020 season — the 50 inning threshold makes Brubaker an official prospect and leaves Keller off the list.
We think of prospects as those who have unreached future potential. While we might disagree on Keller’s future potential, I think we can all agree that he has future potential that he hasn’t yet reached. That makes him a prospect, even if he doesn’t have the official label.
On the other hand, Brubaker gets the official label, which comes with the benefit of the doubt that there’s more to come. Once that “prospect” label disappears, there tends to be some shine that gets removed from a player if he doesn’t have instant MLB success. I’ve seen people refer to this as the “post-prospect” stage. The players in this stage aren’t official prospects, but they do have a chance of a higher future potential. They’re just seeing the chance declining with age.
That’s where some outlets will discount a player like Brubaker, even if he has prospect eligibility. Everyone has their own ranking and evaluating methods. I like the approach by FanGraphs to evaluate prospects based on their first six years in the majors. That does tend to favor younger players, as they’ll be spending more of their prime in the majors as established players, in theory.
Brubaker is in his age 27 season. If you project him sticking in the majors over the next six years, that covers his age 27-32 seasons. Those final few years would, in theory, lead to less production than a similar pitcher who arrived early and pitched from ages 25-30.
This doesn’t mean that 27-year-old Brubaker doesn’t have future value. It also doesn’t mean you should discount him because there’s a hypothetical 25-year-old upgrade that we could have instead. It just means it’s usually better to have a player’s age 25-26 seasons, rather than his age 31-32 seasons.
But let’s forget that argument for a second, and go to our third player: Wil Crowe.
The Pirates added Crowe from the Washington Nationals, along with Eddy Yean, in exchange for Josh Bell. Crowe is in his age 26 season, turning 27 by the end of the year. He’s only 10 months younger than Brubaker, has less experience in the majors, and I would argue that Brubaker easily has better stuff. Crowe benefits from having a wider selection, which turns this into a sort of quality versus quantity aspect to starting pitchers and their pitches.
When I looked at the 2021 Combined Prospect Rankings last week, I found it interesting that Brubaker wasn’t ranked in the FanGraphs top 51, or the MLB Pipeline top 30. He may not qualify for either list, due to service time or age. They may just think he’s not one of the top 51 or 30 prospects in the system.
Brubaker’s exclusion does look interesting next to Crowe, who was ranked inside the Pirates’ top 30 by every outlet. FanGraphs had him at 30 with MLB Pipeline at 21. Baseball America had him 20th, and we had him 24th in the system.
Crowe’s value largely is fueled by his floor. He doesn’t look like much more than a back-of-the-rotation starter, but average control and five average-or-better pitches gives him a good chance of reaching that mark. We rate Brubaker with an above-average fastball and a slider that flashes plus, along with two more pitches that can be average, and the chance for average control. Both guys have the chance for 50 grades across the board with their pitches and control, but Crowe is more likely to see that happen. Brubaker is more likely to be a 2-3 pitch guy, hoping that one of those pitches will keep him in the rotation. There’s more upside for Brubaker, but Crowe is safer.
Which option do you take there, in the “post-prospect” age where a player has limited chances? It sounds better to go with a safer option if he’s not going to get repeat opportunities, but at what point do you give up on a bigger talent?
The Pirates have three pitchers competing for the rotation: Mitch Keller (25), Wil Crowe (26), and JT Brubaker (27). By most standards, the youngest of the group is not a prospect, due to having more experience than the older players. Yet, that non-prospect has the most upside of the group. All three have the chance to be better than what we’ve seen, which is what you want from a prospect.
So, what is a prospect?