First, I should say that I like Shelby. I was excited when the Cardinals went the high risk/ high reward route and drafted the big Texan out of high school. I followed his minor career pretty closely and thought he looked cool in the pictures of him in shades. I dreamed of him coming on as the new ace as Carpenter and Wainwright edged toward retirement. I was concerned when he got into a little trouble in Springfield, and was disturbed when management made much ado about nothing over him showing up to camp underweight by training "the wrong way" in the off-season.
When Shelby was traded, I was conflicted. Like many Cards fans, I wished him a modicum of success with the Braves but not spectacular success. I reserved judgment on who "won" the trade at the start of the season as Shelby was piling up the impressive stats. Now, Shelby has stumbled into a fate you wouldn't wish on your worst enemy (excluding Cubs players). He has now compiled a streak of 20 starts without a win and is just short of a club record for this distinction. Does this mean Shelby has the stats but not the intangibles to be a winner? Is he destined to be the pitcher everyone dreads to see come up for a turn in the rotation because there is the anticipation of an "automatic loss" (think Kip Wells or Mike Maroth from the 2007 team)?
To attempt to answer these questions, I started sorting through the data. Before I looked at the data, I remarked to someone that the Cards would gladly sign Shelby to a contract that covered only the months April and May. While it is true that his W/L splits suggest that he is a much better pitcher at the start of the season: April 9-5, May 7-4, Jun 4-8, Jul 3-6, Aug 2-7, Sep 5-1, his splits with regard to stats are not nearly as skewed.
Having looked at the advanced stats on Fangraphs, he looks like a pretty solid pitcher for situational pitching, including behind in the count, high-leverage, etc. For the Cards, his stats peaked in 2013 and were trending negative for W/L, K/9 and BB/9, and he did not have a reputation for pitching deep into games. From this perspective, it was not surprising that the Cards might consider trading him while his value was high; yet, if just one or two events had gone his way (e.g., keeping the lead in one playoff game), management may have considered his ledger too positive for a trade.
It is difficult to evaluate a players grit or determine whether he is a bulldog in clutch situations. I did witness Shelby coming out of several games "hanging his head", but this would fall into the category of anecdotal evidence.
As far as my personal conclusions, I think there are more questions about Shelby than answers. His stats just don't add up, starting with his career W/L of 31-31 vs era of 3.16. His peripherals are not as good as standard stats, but no one would predict someone with his "stuff" to fall into the black hole he has in terms of going winless, and I would welcome Shelby back as a member of the Cards rotation. Though he has endured a wicked streak of bad luck, it is not unprecedented. The MLB record for consecutive decisions with a loss was 27, set by Anthony Young with the Mets in 1992-93. During the streak, he converted 12 straight save opportunities and pitched 23.6 scoreless innings; he just couldn't get a win. This stretch overlapped a period of 27 winless starts by Young, of which, 13 met the criteria for "quality start"; his career era was 3.89.