The 2011 Phillies Rotation and Game Score

Game Score is one of Bill James’s more well-known creations. It attempts to quantify the effectiveness of a given pitcher’s start by assigning a number from 0 to 100 (50 being average), converting the box score into a single easy-to-interpret metric . While far from perfect, its simplicity make it a useful tool when looking at pitchers on a game-by-game basis. The formula is as follows:

Game Score = 50 + 3(IP) + 2(IP after the 4th) + 1(K) – 2(H) – 4(ER) – 2 (UER) – 1(BB)

Anyway, in another attempt to reflect upon just how awesome last year’s rotation was, I put together a graph that demonstrates each starter’s Game Score for each of his starts in 2011. Sorted from best game to worst game (that’s what “nth best start” on the x-axis refers to), the idea is to perhaps shed some light on how each pitcher performed relative to one another without relying on aggregate season data. For instance, we know that Halladay had a lower ERA than Lee, but how do the best outings from each pitcher compare to one another?

The first thing that jumps out is Lee’s red line that hovers–quite significantly–above everyone else’s lines for the best 15 starts or so. This should be consistent with our memory of his 2011 season: when Lee was on, he was on. The data prove this narrative to be true as he posted a Game Score of 80 or above eight separate times. However, he dips slightly below Halladay for the right side of the graph, indicating that his worse starts were, well, worse. Here we have evidence that Lee was a slightly more polarizing character than Halladay last season. Doc’s flatter curve testifies that he remains a role model when it comes to consistency.

Slightly below them is Hamels, whose line is actually on par with Halladay’s for the majority of the graph. He drops of pretty harshly at the very end as a result of a few awful outings. Next are Oswalt and Worley who both fall quite markedly below the big three. While each put up a handful of dominant starts, the majority of their Game Scores hang in the 40-60 range, suggesting a certain level of mediocrity. It’s probably not fair to hold them to the same standard as Halladay, Lee, or Hamels though.

Some other quick Game Score facts about the 2011 Phillies rotation:

Best Game Score: Cliff Lee with a 92 on April 14th @ Washington (9 IP, 0 R, 12 K, 1 BB, 3 H)
Worst Game Score: Vance Worley with a 10 on May 29 @ NYM (3 IP,  8 R,  1 K, 5 BB, 12 H)
Best average Game Score: Cliff Lee (64.1)
Best standard deviation: Roy Halladay (13.1)