The Diamondbacks 17-11 start has been a huge surprise to the 2017, a complete contrast to the 2016 season where they started 12-16. The biggest differences aside from AJ Pollock being healthy has been the team’s starting pitching. A starting rotation that struggled, pitching to a 5.19 ERA, 4.50 FIP, and 4.25 xFIP. The high-priced acquisitions in Zack Greinke and Shelby Miller along with other pitchers in the rotation uncharacteristically breaking led the team to a 69-93 record and a front office upheaval. The starting rotation was 25th in fWAR at 7.9.
This year, with almost the same players they are pitching much better. The team traded their 2nd best player and a promising OF prospect in order to fetch a once highly-touted pitching prospect in Taijuan Walker from Seattle. Aside from that, the other 4 pitchers were on the 2016 Opening Day rotation. The team suffered a major injury, losing Shelby Miller to Tommy John Surgery after 3 solid starts, putting up a similar fWAR total to all of last year. In fact, the Diamondbacks led MLB in fWAR for the month of April at 3.4. So what’s the change? The pitching coach is still there and not on the hot seat for now.
The pitchers and pitching coaches are relatively the same, but the new front office completely changed the catcher position. Welington Castillo is catching in Baltimore and Tuffy Gosewisch was shown the door. Chris Herrmann was retained, not for his catching prowess, as the 25th player is a solid lefty bat off the bench and can backup 1B and OF a bit. The front office signed Jeff Mathis and Chris Iannetta for $5.5M guaranteed, and while neither guy is a big threat offensively they are much better game callers than Castillo and Herrmann. Mathis, who is an excellent framer, has helped Zack Greinke rebound in a big way despite a significant velocity loss this year.
In terms of fWAR, the Diamondbacks had 3 pitchers in the Top 25. Greinke 13th with 0.9, followed by Taijuan Walker (19th) and Patrick Corbin (21st) at 0.8. Of those 3, Patrick Corbin is probably the biggest story with his bounce-back campaign. Corbin’s slider is now completely back and he’s using it to dominate hitters like he did in his 2013 breakout season. Taijuan Walker has been a solid acquisition through 5 starts, although command issues are still pertinent with him. The stuff has been good as advertised, and on days he can command his fastball is downright impossible to hit.
Here’s how the rotation has fared so far:
FanGraphs Leaderboard.csv
| Name | K/9 | BB/9 | K/BB | HR/9 | K% | BB% | K-BB% | AVG | WHIP | BABIP | LOB% | ERA- | FIP- | xFIP- | ERA | FIP | E-F | xFIP | SIERA | playerid |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Name | K/9 | BB/9 | K/BB | HR/9 | K% | BB% | K-BB% | AVG | WHIP | BABIP | LOB% | ERA- | FIP- | xFIP- | ERA | FIP | E-F | xFIP | SIERA | playerid |
| Taijuan Walker | 10.01 | 2.12 | 4.71 | 0.91 | 26.4 % | 5.6 % | 20.8 % | .233 | 1.15 | .300 | 69.2 % | 89 | 73 | 83 | 3.94 | 3.00 | 0.94 | 3.42 | 3.24 | 11836 |
| Zack Greinke | 9.82 | 1.96 | 5.00 | 1.23 | 26.3 % | 5.3 % | 21.1 % | .257 | 1.23 | .323 | 84.2 % | 72 | 79 | 79 | 3.19 | 3.24 | -0.05 | 3.24 | 3.23 | 1943 |
| Shelby Miller | 8.18 | 4.91 | 1.67 | 0.41 | 20.2 % | 12.1 % | 8.1 % | .230 | 1.45 | .288 | 71.9 % | 92 | 82 | 110 | 4.09 | 3.41 | 0.68 | 4.56 | 4.73 | 10197 |
| Patrick Corbin | 7.64 | 2.80 | 2.73 | 0.76 | 19.6 % | 7.2 % | 12.4 % | .241 | 1.27 | .287 | 79.0 % | 52 | 83 | 97 | 2.29 | 3.42 | -1.13 | 4.01 | 4.08 | 9323 |
| Robbie Ray | 11.57 | 5.04 | 2.29 | 1.19 | 30.2 % | 13.2 % | 17.1 % | .214 | 1.35 | .290 | 79.1 % | 80 | 92 | 81 | 3.56 | 3.82 | -0.26 | 3.32 | 3.74 | 11486 |
| Zack Godley | 10.80 | 5.40 | 2.00 | 1.80 | 27.3 % | 13.6 % | 13.6 % | .211 | 1.40 | .250 | 89.3 % | 81 | 120 | 99 | 3.60 | 5.00 | -1.40 | 4.06 | 4.11 | 14862 |
In the case of all the pitchers, they have ERA-, FIP-, and xFIP- under 100, which is good. Miller is the only pitcher that was above 100 in any of the 3 categories, but he won’t be throwing another pitch for the 2017 season due to Tommy John surgery. The Diamondbacks don’t have a guy who is a clear Ace in the rotation, but they do have a 1-4 rotation that is as good as anyone else’s. That’s been the reason why the team tied the MLB record for consecutive games of 11+ strikeouts with 8, going 5-3 in that stretch. In 7 of those games, the starting pitcher left with the lead.
The first few games of 2017 is an indication of how this rotation would unfold if the right things happened. So far improving the ability to game plan and acquiring catchers that can call games better has yielded results from the rotation. Will it last, probably not always because every pitcher has a stinker start, but if xFIP is a good future indicator, this team will have a very good rotation to contend with and perhaps shock some people like they did in 2011 when they won 94 games and the NL West division title. They have the pitching talent to do so, it comes down to health.