How many future aces are in the Minors?

Twitter is the best. I mean that wholeheartedly too because the platform is perfect for engaging in conversation about the game that we all love. Just last week, this late night tweet from our own Ryan Potter sparked just such a conversation:

I feel like "ace" and even "number 2 starter" are thrown around a bit too loosely when talking about what a pitching prospect might become.

— Ryan Potter (@80GradeWant) April 24, 2013

Now, Ryan's tweet was in regards to the overzealous nature of fans rather than scouts and writers, but it still caused a lengthy exchange on the number of front of the rotation starters in the league and how the ceilings of prospects should be labeled. While I think we all were generally on the same page, it did get me thinking about how many Minor League pitchers are labeled future number 1 or 2 starters?

Before we answer that though, let's take a step back and talk about how many front of the rotation starters are currently in the Majors. While there isn't any clear definition of a number 1 or 2 starter, our twitter conversation₁ and Bryan Grosnick's criteria for an ace give us a good place to start. We are looking for pitchers that threw at least 190 innings and ranked in the top 40 in both ERA- and FIP- last year. Twenty five players met those benchmarks, but I don't think we're quite done yet. A couple of the names on the list (Wade Miley, Kyle Lohse, and Hiroki Kuroda) just don't seem to fit, and our rigid guidelines left a few prominent starters off. After making a few subjective adjustments, our list of number 1 and 2 starters looks like this:

Justin Verlander

Clayton Kershaw

Stephen Strasburg*

Cliff Lee

Felix Hernandez

Yu Darvish

C.C. Sabathia

David Price

Matt Cain

Madison Bumgarner

James Shields

Adam Wainwright

Chris Sale

Jered Weaver*

Max Scherzer

Jake Peavy

R.A. Dickey

Johnny Cueto

Zack Greinke

Jordan Zimmermann

Cole Hamels

Mat Latos

A.J. Burnett

Gio Gonzalez

Jon Lester*

*didn't meet statistical benchmarks in 2012

That list looks about right to me. We could quibble on the exclusion of young starters Matt Moore and Matt Harvey, but I think it's safe to say we have a pretty close to complete list.

If there are roughly 25 frontline starters in the Big Leagues, intuitively we can say that only a handful of current Minor League players will ever join that group. To Ryan's point, though, prospect publications definitely label more than a few players as future 1's and 2's. To find out just how many, I went to two popular prospect hubs, Baseball Prospectus and Baseball America, and examined their team-by-team top 10 prospect lists entering this season. Every time a report referred to a pitcher as a potential "number 1", "number 2", "ace", or "frontline starter" by either site, they were added to my count.

Astoundingly, of the 174 pitchers in the sample, 59 of them were designated future rotation anchors. Understanding that the majority of these claims are ceilings and not actual projections, that number is still quite high. However, is it too high? The total of 59 means about 2 players per organization; in farm systems containing 6 teams each, that seems about right to me. Although only a handful of players will ever reach that potential, 50-60 probably have a 5% or greater chance of developing into an elite pitcher.

The really interesting part to me was that between BP and BA, only 7 pitchers were referred to as future number one starters. The seven were Dylan Bundy, Gerritt Cole, Jose Fernandez, Lucas Giolito, Shelby Miller, Taijuan Walker, and Zack Wheeler. More interestingly, though, only 4 of them - Bundy, Cole, Giolito, and Walker - were deemed future aces by both BP and BA. So, if we are looking for the likely future aces, this much smaller list is a good place to start.

Sure it may be true that fans say things like, "Prospect X is a future Cy-Young Award Winner," too frequently. On the other hand, if they could just learn to rephrase that to, "Prospect X has a chance to receive Cy-Young Award votes someday", they would be quite accurate. As a baseball community, we should just all try to remember that prospects have a wide range of outcomes, and their ceiling is not the most likely final product.

₁ I think the world needs a name for a twitter conversation. Just saying.

Andrew Ball is a writer for Beyond the Box Score, Fake Teams, and Fantasy Ninjas.

You can follow him on twitter @Andrew_Ball.