Following his highly anticipated trade from the San Diego Padres that kicked off the major dealing at this year’s deadline, Drew Pomeranz is now just over a month into his Red Sox career. Pomeranz did not come cheaply, costing the Red Sox one of their top pitching prospects in Anderson Espinoza who, despite currently residing in Low-A ball, has been on the end of Pedro Martinez comparisons (attach as much weight to that as you like). Pomeranz was favored by Dave Dombrowski and the rest of the Red Sox front-office as he offered stability to the back-end of the Red Sox rotation as well as being young, and an asset under team control through 2018. But Boston is a win-now kind of town, and fans get antsy with mediocrity. So, what has the return been thus far on the latest addition to the Red Sox rotation?

(Before we jump into Pomeranz’s first few starts with the Red Sox, it is worth noting the state of the rotation before his arrival in Boston. The starting staff was undeniably the Red Sox’s biggest flaw, constantly undermining an offensive juggernaut and frequently costing winnable games.)

Red Sox rotation – 1st half stats (MLB ranking)

IP BB/9 BABIP ERA FIP WAR 511 (13th) 3.08 (18th) .303 (14th) 4.72 (19th) 4.51 (21st) 5.1 (18th)

The stats don’t read very well for the Red Sox rotation in the first half of 2016, especially not for a team that was making noise throughout that period– and still is– about a potential run deep into October. (Fragility in the rotation was such an issue, Boston’s front office didn’t even try to doublespeak it away, per usual.) Making a move for at least one starter was critical to prolonging the Sox’s hopes of a successful year, and to sufficiently support a league-leading offense. Everyone knew it.

Red Sox rotation – 2nd half stats (MLB ranking)

IP BB/9 BABIP ERA FIP WAR 268.1 (1st) 2.48 (6th) .281 (9th) 3.56 (4th) 3.78 (6th) 5.2 (1st)

The All-Star break clearly did incredible things for the Red Sox rotation, catapulting them into the top third of the Majors across a range of indicators. Now let’s get this out of the way straight off the bat, the trade for Drew Pomeranz is not solely responsible for this upturn in form—that is not the argument of this article. David Price, since the break, has pitched more like an Ace with every start; Rick Porcello has continued to rack up the wins; Steven Wright, though he’s fallen off the pace after a stint on the DL, is still comfortably the #3 starter; and, up until a couple of nights ago at least, Eduardo Rodriguez appeared to have figured a few things out down in Triple-A.

Pomeranz can certainly claim some credit. For Red Sox Nation, the question just how much credit does he deserve? And does that (will that) outweigh the loss of Espinoza?

Let’s take a look at the numbers:

Comparing Drew Pomeranz in San Diego and in Boston

IP/GS BB/9 BABIP ERA FIP HR/FB Padres 6 3.62 .240 2.47 3.15 8.8% Red Sox 5.54 3.25 .310 4.06 4.50 17.4%

An immediate glance at the data shows that the Drew Pomeranz that arrived in Boston has not pitched the same in his first 8 starts as the Drew Pomeranz that dominated a number of NL teams, including the Pirates, Cubs and the Giants, in the first half of the year.

Is this surprising? Not really. Had Pomeranz maintained his first half performances he could have been in speculative conversation for the Cy Young come the end of the year. That’s some jump from a guy who made just 9 starts for the A’s in 2015. Pomeranz had a couple of advantages in San Diego: pitching in pitcher-friendly PetCo Park, and low expectations for the Padres as a team. Suddenly Pomeranz calls Fenway Park home, a hitter-friendly venue, and is facing better quality offenses in the heat of a pennant race. No surprise therefore that Pomeranz’s HR/FB rate has more than doubled.

Drew Pomeranz Pitch Usage

FB (all types) KC CH Padres 50.1% 39.2% 10.7% Red Sox 52.1% 40.9% 7%

Has anything dramatic changed, however, since Drew Pomeranz arrived in Boston? Looking at the data above it appears very little has, save a slight drop in the use of his changeup, which is potentially due to the small sample size of just 8 starts. That there is no noticeable change in pitch velocity would further suggest Pomeranz is simply struggling to adapt to pitching in the American League. With a 4.06 ERA and 4.50 FIP, Pomeranz’s performances are far short of a disaster, just not a replication of the first half in San Diego that saw his trade stock soar.

Some Sox fans might therefore be slightly disappointed with the return on Pomeranz thus far, but what was the alternative? Internal replacement options were explored throughout the season: Sean O’Sullivan demonstrated himself to be the classic AAAA starter; Henry Owens continually threatens to join him in that category. Brian Johnson is still working his way back from anxiety issues earlier in the season and remains an untested option, although likely too much of a risk on whom to pin hopes of a rotation revival. Clay Buchholz has adjusted to life in the bullpen, and despite a couple of encouraging spot-starts, doesn’t appear to be in line for another change of role; the same story goes for Joe Kelly.

When exploring external options, the key for the Red Sox was holding onto top prospects Andrew Benintendi and Yoan Moncada at all costs. In a sellers’ market this July, that unwillingness to include their top prospects out the majority of top-tier starters that were potentially available on the pitching market, including Teheran, Sonny Gray (now debatable in this tier) and Chris Sale. Rentals such as Rich Hill and Andrew Cashner were overly expensive for 3 months of service before free agency and the Sox landed on Pomeranz as the perfect fit. He offered team control, youth, and could be acquired at a non-prohibitive cost. Sure, the Padres may have gained a potential stud in Espinoza, but we’re still many years away from knowing if he will pan out. A lot can happen between Single-A and the Majors.

Whilst struggling to adjust to a new environment and pitching in the AL East initially, Pomeranz has nevertheless offered what the Red Sox so desperately craved: stability. His individual stats have declined from the extremely strong first half to 2016, he’s still serving the Red Sox as a #4 starter that can consistently offer reasonable starts, taking the pressure off David Price in particular. The Red Sox knew they were not adding an Ace: Pomeranz’s ceiling is most likely a #2 guy, but more likely will settle into a #3 role in time. His presence, combined with other factors, has given the Red Sox a much better chance of making, and going deep into, October.

Note: All Stats obtained from www.FanGraphs.com prior to Pomeranz’ 8/30 start against the Rays in which he went 6.2 innings, allowed 3 earned runs, and struck out 8.

-Andrew Poole