Here are a few things we know about James Shields: he’s been a 200+ inning workhorse for the last six years, has exhibited excellent control and durability, and struck out batters at a higher rate in 2012 (8.82 K/9) than ever before, after finding an extra notch on his velocity.
We know that Shields is one of the best pitchers in the AL, and we know he is easily the best pitcher on the Kansas City Royals staff right now.
By those indications, fans should expect Big Game James to live up to his namesake and be a the type of pitcher who is capable of leading the once AL Central underdogs out of the division’s basement.
Yet, there are some other things that we know about Shields. We know that he has a significant home/road split, and his career ERA when not pitching at home is a pedestrian 4.54 over 674.2 innings. We know he gives up a lot more homers when not at Tropicana field, with a rate that jumps from 0.91 to 1.41 HR/9. In the 262 innings he has pitched against the Royals’ divisional rivals over his career, Shields has a 4.15/1.34 ERA/WHIP.
And what about the starts at Kaufmann Stadium? Well, he’s not going to be pitching against the Royals anytime soon, but he has a 6.38/1.67 ERA/WHIP there.
All of which is to say that while Shields is still undoubtedly an excellent pitcher, he might just end up going through a little bit of regression with his new team in 2013. There are likely going to be a few more homers, and a few less quality starts, and he’s probably not going to go through the season with a ERA in the low-3s.
But how far will the numbers fall, and how much will it matter? Well, that depends on what you mean by regression. 200+ innings is going to be valuable to a team in almost all cases, and it’s worth mentioning that even in Shields’ worst year where he posted a BABIP-afflicted 5.18/1.46 ERA/WHIP, he was still a 2.0 fWAR pitcher because of his innings-eating ability and an otherwise excellent 3.67 K/BB.
By comparison, the most valuable starting pitcher for the Royals last season was Luis Mendoza at 1.7 fWAR.
Still, if the past seven years are indication, playing in an outdoor park will likely shoot Shields’ numbers up a bit. But even at a low-4s ERA and 1.25-ish WHIP, Shields could very easily still be a 4+ fWAR pitcher for the Royals next year. The stuff will still be there, and he will go out every time to pitch all nine innings, even if more of those innings will be dodgier than what he’s been used to over the last couple of seasons.
The expectations of Shields being a true knockout ace might be a bit optimistic, but this is someone who could still lead the team’s staff, even with numbers that you might normally associate with a number-two pitcher.