Sunday, May 30, 2010
"Superior Start" unveiled
By Albert Larcada & Katie Sharp
Avid TMI readers may recall that during spring training, we took our first foray into trying to retool the quality start metric (if you don’t recall, click this link).
With the Rangers and Twins dueling on Sunday Night Baseball at 8 eastern this evening, and lots of talk over the last two seasons about Nolan Ryan’s efforts to fix the Rangers starting pitching staff, we thought it would be an appropriate time to take a look at some results, of which Ryan would figure to be most proud.
The results of our initial study (done via regression analysis) told us that the two elements of a pitching line that best predicted whether a team won or lost were the starters innings pitched and the number of earned runs allowed.
Using the data from the regression, we were able to figure out the team’s chance of winning for any possible innings/earned runs combination by a starting pitcher. And finally, we defined our “Superior Start” statistic as any outing where the starter gave his team at least a 75 percent chance of winning the game.
Now that we’ve passed the quarter pole in the baseball season, let's take a look at some leaderboards.
Ubaldo Jimenez and Roy Halladay top our list for pitchers with the most “Superior Starts” with seven such outings. Jimenez has completely baffled hitters this season. His league and park adjusted ERA+ this season is 515, over 150 points better than second-place Jaime Garcia. According to our friends at AccuScore, Jimenez actually has a 26 percent chance of winning 25+ games, a feat which has not been accomplished since Bob Welch in 1990. Halladay, fresh off of his perfect game, has kept the all-of-a-sudden offensively challenged Phillies afloat in his first season in Philadelphia.
And with a hat tip to Tom Tango, we now bring you our "Inferior Start" metric. These are the pitchers who have the most starts this season with an innings/earned runs combination that gives the team less than a 25 percent chance of winning that game.
As you can see, Charlie Morton tops (or bottoms?) this list of inferiority. All six of Morton's Inferior Starts have actually had a team win probability less than 19 percent, well below our 25 percent threshold.
Interestingly, our Inferior Starts leader Charlie Morton has a 1-9 record, which is the inverse of our Superior Starts leader Ubaldo Jimenez, who is 9-1.
As for tonight’s starters, Scott Baker enters with a pair of Superior Starts for the Twins, one fewer than team leader Francisco Liriano, and one more than his opposing moundsman, Rangers starter, Derek Holland. Baker also has a pair of Inferior Starts, though none have come in the month of May.
We will be updating this leader board periodically throughout the season. Hopefully this sheds a little more light on who is a quality starter, and who is a superior one. We think we can come up with something for which both the math and Nolan Ryan agree.
Alok Pattani and Mark Simon also contributed to this project.