Montero is a highly touted hitting prospect with no real defensive position in the big leagues. He was likely to spend much of this year in the DH spot, which is highly unusual for a rookie. When you consider that the Yankees will have to move the aging A-Rod to that role in the near future, it made sense to move Montero if they could get an impact player back in return. And they certainly did.
The Yankees' biggest need was filling out the starting rotation. Last year, they managed to get by with some luck from Freddy Garcia and Bartolo Colon, but now they have two legitimate starters in Pineda and Hiroki Kuroda to compliment CC Sabathia at the top of their rotation.
The biggest question, of course, is how Pineda's stuff will translate to the hitter-friendly Bronx (and Boston, and Toronto for that matter).
In his rookie season, Pineda put up some tremendous numbers. He finished sixth in K% in all of baseball, mere tenths of a percent behind Justin Verlander. And his BB%, while not league-leading, was still under 8% and right on par with guys like Mat Latos.
A guy that misses that many bats should be successful in any environment, provided he keeps his walks down. However, Safeco isn't just any environment, it's one of the friendliest parks to pitchers in all of baseball. In fact, next to San Diego, it is has been the hardest park to score runs in since 2006 (park factor of 96). Safeco is also the 9th more difficult park to hit a home run in over that same period of time.
Contrast that with Yankee Stadium. That environment is the sixth friendliest to run scoring and the friendliest to home runs.
Even with Pineda sporting a GB/FB ratio below one (44.8% FB% in 2011), his stuff should play very well in New York. If you look at ERA estimators that factor in batted ball profiles, Pineda still comes out looking like a top of the rotation starter. Last year, Pineda posted a tERA of 3.42 and a SIERA of 3.36. Both of those metrics take a pitchers' batted ball profile into account when estimating their ERA. Those types of numbers easily slot Pineda in as a strong, long-term #2 behind Sabathia.
Of course, Pineda has only one season in the majors unders his belt, so there is always the question of whether he can replicate or even improve upon late season. Given his numbers in the minors, however, the Pineda we saw in Seattle is not drastically different than Pineda the prospect.
The other concern is how well he fares from a durability standpoint in his second year as a full time starter. In 2011, he started 28 games and threw 171 innings. In 2010, he started 25 games and threw 139.1 innings between AA and AAA. 42 innings isn't a huge jump, but it's an increase nonetheless on a young arm. Pineda did throw 138 innings in 2008 while in single A, and with his big frame the question of durability in 2012 may not be as important.
If the Yankees were going to move Montero they could have done a lot worse than a 23 year-old that misses bats like Pineda does. Like the Reds earlier this offseason, the Yankees moved a young bat for a young starter, and the latter was clearly their bigger area of need.