A player changing teams brings up interesting questions. Will the change impact their performance? How much was the player benefiting from the environment, and how much was the player’s ability?
Last season, there was a clear difference between Jeremy Guthrie, “Coors Field pitcher” and Jeremy Guthrie, “any other stadium pitcher”. This year, the question moves to James Shields. The key acquisition of the Royals offseason could see a big difference in his numbers after a career in Tampa Bay.
The key factor that may spell doom in 2013 is Kansas City’s defensive abilities. It’s not the first time and perhaps not the last that the Royals are compared to the Tampa Bay Rays in regards to their respective defensive efficiency. Statistically, the Rays were the second best team in the majors. The Royals were third worst. The thinking is, then, that Shields will be going to a new team that isn’t as solid defensively as the Rays, more balls will go for hits, meaning more baserunners, and more opportunity to give up runs.
It’s something to keep in mind.
Perhaps a full season of Salvador Perez and Lorenzo Cain plus no involvement at all of Yuniesky Betancourt can improve Kansas City’s numbers. Perhaps Shields himself can help how they look, statistically. Last year, he had a 52.3% ground ball rate – a career high. Are those two factors enough to get the Royals into the middle of the pack defensively? Possibly, but it can’t be assumed.
It’s not all doom, though. Shields is also moving from the AL East to the AL Central, meaning he’ll face the New York Yankees and Boston Red Sox far fewer times than he otherwise would have. Last season, 14 of his 33 starts came against AL East teams, with six coming against the Yankees. In his career, 94 of his 217 starts have been against AL East teams. He’s made 40 starts against non-Royals AL Central teams. The assumption is that in facing Boston and New York often, he’s suffered from facing high-salary, All-Star-laden lineups.
It’s true that Boston and New York have done damage against him. In his career, he’s got a 4.56 ERA against each AL East powerhouse. His overall career numbers against the division improve when also considering the Toronto Blue Jays and Baltimore Orioles. Overall, his career ERA against the AL East is 3.98 in 621.1 innings.
Against the AL Central in his career, Shields has a 4.16 ERA in 262 career innings (again, omitting any games against the Royals). AL Central teams have gotten more hits against Shields and the Rays and have reached base more often (.296 OBP allowed against the AL East versus a .316 OBP against AL Central teams).
So perhaps that switch from AL East to AL Central won’t help him that much.
His career numbers, though, also include his early years and his rough 2010 season. More recently (that is in 2011 and 2012) Shields has been among the better pitchers in the American League, keeping his walkrate low but striking out a higher percentage of batters.
Just looking at 2012, then, Shields performed better against the AL Central than the AL East. In 94.1 innings against AL East teams, he had an ERA of 4.21 whereas against Central teams it was 3.60 (in 50 innings). More batters reached when Shields faced the Central, but the East teams hit more homers (13 in 94.1 innings compared to just two in 50 innings).
We can’t really expect Shields to surrender only two homers in 50 innings, but it’s probably safe to say that Shields won’t give up as many homers facing more Central teams than East teams in 2013.
The information suggests that Central teams make more contact and get more singles, but AL East teams walk more and hit more homers (and also strike out more). None of it is definitive.
We should also consider that Shields will pitch more games in Kauffman Stadium. In his career, he’s given up one homer in 24 innings at the K. Some of that is due to the stadium depressing home run numbers. Part of that is also due to the Royals having pretty thin home run numbers through Shields’s career. In Tampa, he gave up less than a homer per nine innings (0.90 HR/9), less than his career average of 1.1 HR/9. Tropicana Field is more of a pitchers’ park; Kauffman Stadium is fairly average (but is a lower home run environment).
So let’s make a call here. It feels right to suggest that Shields facing the Central more often will help him simply because the threat of the home run is lessened, and he still has strikeout and ground out abilities to get out of innings when he does put runners on. Is the change going to be significant? I doubt it, but I do think he’ll perform slightly better if the Royals defense can show improvement. If the defense doesn’t, it may be a wash.
(Info came from Baseball-Reference and team-by-team numbers can be found here.)