Here's hoping Steven Strasburg's great game last night is indicative of great things to come. But how about some context after the excitement from his hyped, and admittedly very exciting, debut has died off? After all, how many wins will Strasburg really be worth to the Nationals? Answering this question proved to be a lot harder than I anticipated, but, several rushed assumptions later, here are my projections:
My first question was how much better will Strasburg be than the pitchers who would be playing in his spot had he not played this year? That is, will Strasburg better the collective efforts that various other Nationals pitchers would have made in his absence? After reading Davenport and Woolner's insightful article on Bill James' famous "Pythagorean Theorem," I decided to use the "Pythagorean method" which the authors employ at the end of the article. For an individual pitcher, the Pythagorean method requires only runs scored and runs allowed during a pitcher's season, and that pitcher's decisions (the games pitched by a pitcher that end in either a win or loss) to predict what his record "should" be.
I will spare you the details, but will tell you that I used some assumptions about how the Nationals offense/defense/pitching would perform and took various other potentially dubious shortcuts to get the necessary inputs.
For Strasburg's numbers, I relied upon this article from the Hardball Times, except for IP, which I thought was too low. I also had to make my own predictions about which pitchers would be pitching in Strasburg's position. I decided that roster moves and managerial decisions would have lead Craig Stammen, John Lannan, and some third pitcher (Jason Marquis, Luis Atilano, J.D. Martin, Jordan Zimmerman or someone comparable) to fill the Strasburg void.