The Red Sox and Giants struck a Saturday morning near-trading deadline special, with Jake Peavy headed west in exchange for pitching prospects Edwin Escobar and Heath Hembree, with the clubs splitting Peavy’s $5M remaining 2014 salary. As with most of this month’s trades to date, real, actual, solid prospects were netted by the selling club. In this case, they’re both pretty close to big league ready. Before anyone rushes to call this a clear win for the Giants – Peavy is 1-9, 4.72, for the season, after all – let’s take a closer look at what the Giants are getting, and how Peavy fits into his new environment.

Truth be told, post-peak Jake Peavy was never a particularly good fit in Fenway Park. He has always been a fairly extreme fly ball pitcher, and that in general is not a good thing to be in that environment. Utilizing my own 2013 park factors, based on granular batted ball data, Fenway had the second highest fly ball park factor, at a whopping 151.1. It’s been ever worse in 2014, at 165.5. Routine fly balls often become doubles in Fenway. Overall, including all batted ball types, Fenway had the highest doubles park factor in 2013, at 125.

The environment that Peavy is headed to is much, much different. In 2013, AT&T Park had the 3rd LOWEST fly ball park factor at 76.0, and thus far in 2014, it has been even lower, at 62.3. There is virtually zero chance to hit the ball out of the park to the right of center field, unless you drive it right down the line.

If you took all of Peavy’s 2013 fly balls allowed, and put half of them in Fenway Park, he would have allowed a .310 AVG-.870 SLG, 130 production relative to the MLB average. Put those same fly balls into AT&T Park, and it drops to .286 AVG-.777 SLG. This is not an insignificant difference. Thus far in 2014, Peavy has already allowed a whopping 31 doubles, 11 of them on fly balls. He has allowed a .298 AVG-.847 SLG on fly balls, 126 production relative to the league. Expect that figure to drop down to near MLB average from now through season’s end.

There’s some other positive regression that should be coming due for the Giants. Hitters are batting .778 AVG-1.159 SLG on line drives allowed by Peavy so far this season, way above the MLB average of .662 AVG-.874 SLG. Let’s not go crazy here – this is post-peak Peavy after all, a guy with slightly below MLB average K and BB rates, not the gaudy figures he put up back in his salad days with the Padres. He is way better than what his traditional numbers say he is this season, however – he is a massive popup generator (11.9%), and his stuff, while not what it used to be, has not deteriorated materially.

He has been a solid if somewhat unspectacular contact manager throughout his career – his career unadjusted contact score, the production he has allowed on batted balls, unadjusted for context, is 93.1, well better than league average. The Giants are getting what should be – in their ballpark – an average to slightly above average major league starter, who has been through the postseason wars recently, and has a great deal of experience pitching in NL West ballparks. This is a good fit for them, and in the NL’s wild seven teams for six spots pennant race, he slots right into the spot vacated by the injured Matt Cain in the rotation. The difference between Yusmeiro Petit and Jake Peavy the rest of the way could be the difference between the wild card and going home, or the difference between a one-game wild card lottery ticket and an NL West title.

Now let’s take a look at the Red Sox’ return. Escobar, 22, is the key piece here. Again, don’t sweat the traditional stats – he’s 2-8, 5.11, at Triple-A Fresno. In fact, the key stats for Escobar are his age and his level of competition. Each season, I compile an ordered list of minor league position player and starting pitcher prospects based on a sliding scale of production and age relative to level of competition. Escobar has fared extremely well on this list, ranking #60 in 2012, #10 in 2013 and #46 at midseason 2014. While this is more of a follow list than anything else – I don’t get overly caught up in the exact rankings – I do now have 22 years of history to draw upon, and to see where current major leaguers ranked when they were prospects. The closest active matches to Escobar are:

– Jake Odorizzi – 4 years in Top 69 – Peak rank #30

– Yordano Ventura – 3 years in Top 69 – Peak rank #23

– Ricky Nolasco – 3 years in Top 55 – Peak rank #40

– Jon Niese – 4 years in Top 65 – Peak rank #52

– Matt Garza – 3 years in Top 49 – Peak rank #12

Oh, and just for fun, Jake Peavy had 3 years in the Top 11, and peaked at #3. Escobar has an above average fastball for a lefty, his changeup flashes above average, and his slider should be an average pitch at the major league level. He has struggled mightily against the opposite hand this season, for the first time in his pro career. If he can overcome this, he should be a contender for a rotation slot in Boston as soon as next spring. He could be what they thought they were getting in Felix Doubront, a solid mid-rotation starter.

Hembree, 25, is a little less exciting, but is what he is – a big man with a big arm, with a slider that can be filthy to righties. He is a born and bred reliever going back to his college days, a one inning per outing guy who has now been at Triple-A Fresno for the better part of three seasons, cracking the Giants’ pen only briefly. He’s not likely to be a future MLB closer, and will need to figure out a way to get big league lefties out – he’s given up 33 baserunners in 14 2/3 innings against them in Fresno this season. That said, he has the raw materials to become a Matt Albers/Scott Atchison type for Boston, a 7th inning guy who will get righties out.

It isn’t either of these two clubs’ first trading deadline rodeo – three very large pieces of hardware have been won by them in the very recent past. The Giants understand how precarious their playoff perch is at present, and how Peavy should fit better in their home environment. They don’t have a loaded system, but pitching is their strong suit, and while Escobar is now gone, Kyle Crick, Adalberto Mejia and Clayton Blackburn remain. The Red Sox haven’t totally given up in the thoroughly mediocre AL East, but they knew a solid offer when they saw one, realize Peavy isn’t a perfect fit in Fenway, and can now give some talented young hurlers – who are better fits – a late-season opportunity. Kudos to both clubs on this one.