Shields has a 3.89 career ERA, and a 3.15 ERA over the past two years. (Mind you, three years ago he had a 5.18 ERA and led the AL in hits, earned runs, and home runs allowed.) But here's the thing: In Tampa Bay, he played in one of the best pitchers' parks in baseball, in front of one of the best defenses in baseball, for one of the best managers in baseball. He brings none of those things with him to Kansas City.
Ballpark? For his career, Shields has a 3.33 ERA when pitching at Tropicana Field. When pitching anywhere else, he has a 4.54 ERA.
Defense? By defensive efficiency — a measure of what percentage of the time a defense turns a ball in play into an out — the Rays have had the best or second-best defense in the major leagues for each of the past three years. By comparison, over the past three seasons the
Royals have ranked 28th, 24th, and 26th in defensive efficiency.