Early Trends From Tandem Pitching

I have been very interested in the tandem pitching system put in place by the Astros this year in their minor league system.  Even though we are dealing with a very small sample, I was curious if there were players who were performing more effectively in  the starter role verses the reliever role and who was better at shutting the door than opening it.  I was also interested in seeing who was performing well regardless of what role they were in. Let's look at the pitchers at Quad Cities, Lancaster, & Corpus Christi since their rotation hasn't been cannibalized like OKC's has.

Pitchers Post Work Stretch @ Spring Training - Photo by AppyAstros (Use by permission only)

Please let me start:
Here are the guys who have the biggest difference between their starter ERA (S-ERA) and their reliever ERA (R-ERA)

Luis Cruz (Lan)  -7.38
S-ERA 0.93 (9 2/3 IP)
R-ERA 8.31 (8 2/3 IP)
12 of the 16 hits allowed have been as a reliever.  

Mike Hauschild (QC) -5.85
S-ERA 0.90 (10 IP) 
R-ERA 6.75 (5 1/3 IP)
Hausechild's numbers don't jump out with any big splits.  Possibly a case of small sample size since he excelled in the reliever role in Greeneville last season.

Bobby Doran (CC) -4.50

S-ERA 0.90 (10 IP)
R-ERA 5.40 (8 1/3 IP)
Both HR surrendered came as a reliever.  Has walked four as a reliever verses just one as a starter.

No, you go ahead. I insist:
These are the guys who have performed more effectively as relievers than as starters.  Their S-ERA is much higher than their R-ERA.


David Rollins (Lan) +7.45
S-ERA 7.45 (9 2/3 IP)
R-ERA 0.00 (12 IP)
14 of his 22 Ks have come as a reliever

Joe Bircher (QC) +7.00
S-ERA 7.00 (9 IP)
R-ERA 0.00 (7 IP)
All his HR (2) and Walks (3) have come as a starter.

Tyson Perez (Lan) +5.26
S-ERA 6.39 (12 2/3 IP)
R-ERA 1.13 (8 IP)
Has 18 hits and seven walks as a starter against six hits and no walks as a reliever.

Just give me the ball!
These guys have performed equally well regardless of which half of the tandem role they fulfilled.

Asher Wojciechowski (CC) +1.20
S-ERA 1.20 (15 IP)
R-ERA 0.00 (8 IP)

Lance McCullers Jr (QC) -.39
S-ERA 2.45 (7 1/3 IP)
R-ERA 2.84 (6 1/3 IP)

Vincent Velasquez (QC) +2.70
S-ERA 2.70 (10 IP)
R-ERA 0.00 (8 IP)

In looking at the stats, it looks like two guys have already settled into full time starter roles.  Jake Buchanan has made four straight starts and Michael Foltynewicz has made three starts in a row. (4/27/13 - figures as soon as point this out, Folty pitched in relief last night.)