Over the last few years we've come to expect the Padres and Mariners' front offices to operate on opposite ends of the spectrum, and with the Baek deal we're seeing one of the main differences up close and personal.
Baek was a victim of the numbers game in Seattle -- the numbers that are printed on the checks -- and gets dealt to the other bummer team on the west coast despite being better than Jarrod Washburn.
Turning 29 today Baek's issues have been with the long ball and this year walking nearly 4 per nine. In PETCO Baek's high flyball tendencies should be covered better and despite the Padres defense being middle of the pack (.696 DEF_EFF) it's still quite a bit better than Seattle's (.683).
Paul DePodesta explained some of the specifics of the deal here and says a lot of Baek's value is as a starter, but let's examine what Baek's peripherals and such say about his performance:
11.2% LD, .240 BABIP, 48% FB, 12.8% HR/FB, 4.5 K/9, 3.9 BB/9, 1.8 HR/9
With such a high flyball rate naturally Baek is going to give up some jacks however 12.8% seems pretty high and set for a regression to his caerer average of 9.3%.
Best case scenario for the Padres is Baek becoming an average pitcher this season and gives them a few decent starts. The Mariners though could've just as easily gotten rid of Washburn and placed Baek in his role and probably would've seen an increase int output.