The last week has perhaps given us a bit of an insight into the approach GM Dave Stewart is taking when it comes to rebuilding the team. We heard from President Derrick Hall earlier in the week, it's going to be aimed at building a team that can compete over the longer term - first and foremost, through pitching and defense. That is a philosophy which appears to be borne out by the acquisitions this week of Robbie Ray, Allen Webster and Rubby de la Rosa, who add to the immediate rotation candidates, with the prospects received for Miguel Montero representing potential further in the future.
Stewart appears also to be adopting an approach based on depth: rather than paying a higher price for a pitcher who is already established at the front of the rotation, he is stockpiling younger, cheaper arms with potential upside. de la Rosa is a prime example: he could be a top-of-rotation starter, particularly if he can add a reliable third pitch to his fastball/change-up combo. Get enough of these, and it becomes a numbers game. Even if there's only a 10% change of a player breaking out, if you have half a dozen pitchers like that, the odds of one or more doing so become close to 50/50.
Further to de la Rosa, virtually the first point Dave Stewart made during last night's conference call, when asked about the motivation behind the trade, was to say that, "We haven't had any real power arms in our organization since Randy Johnson." There's some truth to that. In 2014, the Diamondbacks' pitching staff, collectively, had the slowest average fastball velocity of any team in the majors, at just 90.0 mph, and we haven't been ranked higher than 29th since 2010. Among starters, we were down at 89.5 mph, dead last there too, and it wasn't even close - the 29th-placed team was the same distance from the 17th-placed team as they were from Arizona.
That isn't necessarily a bad thing - that 29th-place team came from San Francisco, who didn't do too badly this year. But I get the idea that nothing but soft-tossers might make opposing hitters too comfortable, over the course of a series. Stewart expressed the hope that the arrival of Rubby de la Rose and Allen Webster would allow the team to mix things up, not allowing batters to settle into a comfort zone. For comparison, de la Rosa's average fastball last season was 94.0 mph - that's harder than any of the 11 starters we used last season, who ranged from 92.9 mph (Brandon McCarthy) down to 85.4 mph (Bronson Arroyo, albeit making half his starts without a UCL).
Indeed, Stewart was almost spot on with his assessment. To find the last D-backs starter (min. 100 IP) to average above 94 mph with his fastball, you have to go all the way back to 2002, and the Big Unit, who reached 94.5 mph. Since then, the closest was Edwin Jackson, who matched 94 in 2010 - though he offers a reminder that raw stuff does not necessarily translate into success, when you have no real idea of where the ball is going [see also: Cahill, Trevor]. However, analysis shows the harder you throw, the more likely you are to get a swing and miss, and this will naturally tend to result in a higher K-rate and lower ERA.
What was also interesting in Stewart's comment were the names he touted, at this point, as likely members of our starting rotation on Opening Day 2015: Josh Collmenter, de la Rosa, Jeremy Hellickson and Webster, with a competition in spring training for the fifth spot. Or rather, what was most interesting was the name not mentioned: Trevor Cahill. He may be tied with Aaron Hill as the most-expensive Diamondback in 2015, but it seems apparent that the new regime has no particular allegiance to him. If his control issues aren't sorted, and his performance doesn't merit a roster spot, they seem willing to cut bait.
Also of note: none of the four starters currently penciled in for the Opening Day 2015 rotation, were in the rotation on Opening Day 2014. According to Stewart, the last spot could be any one of Chase Anderson, Trevor Cahill, Andrew Chafin, Randall Delgado, Daniel Hudson, Vidal Nuño and Robbie Ray, and unless it goes to Cahill or Delgado, it will mean a complete re-invention of the Diamondbacks rotation in a single year. Some of this is due to injury - Arroyo would likely have been in there, if he wasn't rehabbing from TJ - but it's also testament to the new broom. with the majority of our likely 2015 rotation not even being with the organization at the end of 2014.
The big question is whether the trade is a good one, and is hard to say at this point in time. I tend to think Miley is not as bad as he was in 2014 - but nor is he as good as he was in 2013. He had the same FIP of 3.98 in both seasons, and his overall ERA for 2013-14 was 3.94, so I think around there, which works out as an ERA+ of 97, is probably close to his "true" talent level. That would be solid, but unexceptional: certainly fine at league minimum, though becoming increasingly less so as he moves through arbitration, so I can see the team's motivation for moving Wade.
Can de la Rosa and Webster do better? To get all GrammarNazi on you, they certainly can; the question is whether they will. It will be a good test of pitching consultant Dave Duncan, whom it would appear was brought on specifically for this kind of project: hurlers with potential, but also obvious flaws in their current repertoire [no third pitch for de la Rosa; too many walks for Webster]. The trade definitely stands in contrast to most of the big ones during the Towers era, which saw potential and upside dealt away for performance with a longer track record e.g. Parker for Cahill, Eaton/Skaggs for Trumbo. Given how badly that worked out, I'm definitely not averse to a change in tack.