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Diamondbacks Rotation: Depth Chart Discussion

In the coming weeks, we’ll be covering each team’s potential depth charts in an effort to shine a spotlight on the interesting playing time battles that will be waged this spring. Obviously none of these depth charts are set in stone — rather they should function to focus your attention in the right places to find cheap fantasy value.

This week, we begin a team-by-team look at depth charts in the infield, outfield, starting rotation and bullpen, and we’ll be highlighting position battles and any other interesting stories. We start with the National League West division and today I will be analyzing the starting rotation in Arizona. The top four are pretty much set in stone, with Ian Kennedy, Trevor Cahill, Wade Miley and Brandon McCarthy slotted in. That last spot, however, is very much up for grabs and is worth monitoring.

Early Depth Chart:
Ian Kennedy
Brandon McCarthy
Trevor Cahill
Wade Miley
Patrick Corbin
Tyler Skaggs
Randall Delgado
Daniel Hudson

The candidates to open the season as the fifth starter are the recently acquired Randall Delgado, 2012 rookie Patrick Corbin and 2013 rookie Tyler Skaggs. Let’s first compare how each performed in their entire minor league careers:

Player IP K/9 BB/9 GB%
Randall Delgado 582.1 9.6 3.4 Low-40%
Patrick Corbin 430.2 8.4 2.3 Mid-to-high 40%
Tyler Skaggs 389.0 9.9 2.6 Low-to-mid 40%

Now for a comparison of just their respective Triple-A numbers:

Player IP K/9 BB/9 GB%
Randall Delgado, Triple-A 66.0 10.4 4.4 43.4%
Patrick Corbin, Triple-A 52.1 9.5 2.6 50.0%
Tyler Skaggs, Triple-A 52.2 7.7 2.7 45.7%

The trio have all thrown a relatively similar number of innings at Triple-A, which makes it easier to compare. Corbin has the clear edge in overall skill set as those peripherals would result in the lowest SIERA mark of the three. Corbin actually kicked his strikeout rate up a notch compared with his minor league career average, which is always a good sign. Delgado did as well, but that came along with control issues, so his K/BB ratio actually declined.

Skaggs was the only pitcher whose strikeout rate took a dive. His fastball velocity is the lowest of the three pitchers, so it’s possible he’s one of those guys who can get by in the minors, but simply doesn’t have enough velocity to see his skills translate. Or, it could just be small sample nothingness of course.

So based solely on minor league history, I would rank them Corbin, Delgado and then Skaggs for potential fantasy value. Delgado and Skaggs’ expected ERA based on the Triple-A skills are similar, but the additional strikeouts offset the slightly worse WHIP and push Delgado slightly ahead.

Now let’s check in on their Major League performances so far:

Player IP K/9 BB/9 GB% SIERA
Randall Delgado 127.2 6.6 4.0 46.7% 4.28
Patrick Corbin 107.0 7.2 2.1 45.7% 3.71
Tyler Skaggs 29.1 6.4 4.0 34.0% 4.98

While the samples are still quite small, and tiny for Skaggs, once again, Corbin has pitched the best of the three. Delgado’s strong minor league strikeout rate has yet to manifest in the Majors, even though his below average control has come along for the ride. And Skaggs’ excellent minor league control didn’t immediately translate during his cup of coffee last season, as he struggled to throw first-pitch strikes. Don’t let Corbin’s bloated actual ERA of 4.54 fool you. An inflated HR/FB rate and BABIP bit him, though some of the BABIP could be blamed on a high line drive rate, which in itself has a low year-to-year correlation.

Last, let’s check out the projections for the upcoming season. I chose to only look at Steamer since those are my favorite for pitcher projections:

Player IP K/9 BB/9 HR/9 ERA WHIP
Randall Delgado 131.0 7.0 4.2 0.9 4.45 1.45
Patrick Corbin 151.0 6.9 2.9 0.9 4.04 1.32
Tyler Skaggs 120.0 7.1 3.7 1.1 4.49 1.41

While Steamer doesn’t expect any of these young lads to generate mixed league fantasy value, it’s yet another point in Corbin’s favor that confirms he is currently the best of the lot. I have no idea what the Diamondbacks plan to do and how much weight they will put on spring training performance, but NL-Only leaguers should speculate on Corbin.

I would be remiss if I failed to mention Daniel Hudson. The young right-hander underwent Tommy John surgery last July and early reports suggest that he is “hopeful” he can return sometime in July. That would give the fifth starter winner more than enough time to prove whether or not he should stick and I don’t expect much from Hudson just a year removed from the procedure anyway.