Monday, March 22, 2010

Rox Talk - Pitching Rotations Part I

Pitching Rotation - Part I

"Good pitching will always stop good hitting and vice-versa" - Casey Stengel

Is being named the number one starter a curse? Initially, on a gut level, my view is that for the Rox whenever our new number one starts the season he limps out of it with an injury or has a forgettable season. 2008 was Francis's year coming off a great 2007. Shoulder problems ended 2008 for him and 2009 was lost to surgery. Cook was the 2008 pitcher but upon being named number one for 2009 struggled mightily throughout the season and lost the tag early on and limped through Aug/Sept with an injury. So with great trepidation I realize that 2009 is Jimenez's year and he has been awarded that number one tag for 2010. So does being the number one starter cause more stress because the pitcher has to go up against the other teams number one starters?

The underlying question then is what does it mean to be a number one starter? Ideally the number one gets to open the season and be in the pole position throughout the year. Teams hope to ride that best arm to lots of victories. I took last year's schedule and ran through a 5 man rotation. The only condition I had was that the number one starter had to have a minimum of 4 days rest and always pitched on that 5th day. The rest of the rotation fell into the remaining spots. Without too much work I established a schedule where the other starters only had to pitch on 3 days rest four separate times. The result of this was that the number one starter got 36 starts followed by 35 for the number two, 35 for the number three, 32 for the number four, and 24 for the number five. For comparison sake the actual totals for 2009 amounted to 33 for Jimenez, 33 for Marquis, 32 for de la Rosa, 30 for Hammel, 27 for Cook, and 7 by others. So baseball's prevailing strategy then is to get the most out of your best arm and give your best arms a chance for more appearances and thus hopefully win more games?

Sounds like sound strategy but wait (!), this is what every major league team is trying to do so in essence the Rox number one starter is getting saddled with facing all the other number one starters. So two questions spring to mind, 1) Does this pitching rotation play out for an entire season (i.e. number ones face off more) and 2) If number ones continuously pitch against one another would it make sense to not throw your number one starter but have him start somewhere else?

First thing I noted out of the gate while studying this was that starting rotations are rarely fixed. Injuries, off days, and travel schedules allow for a pitching rotation in constant flux. Also while it is easy to establish a rotation in Spring Training, rarely does it end up the same way at the end. Then the next big question is what defines a number one vs number two? Is it wins, innings pitched, or something more exotic like WAR? Of course to analyze this you have to look back at an already finished year which can taint the results because by establishing your opponents rotation based on the end of year numbers you are sort of compromising your analysis if in fact rotation orders determines success. For instance de la Rosa won 16 games in the number three spot last year. So he either faced a lot of other number three starters and was better and thus won more, or perhaps if he was bumped up to a number two starter he might not have won as many games or (and a big or) pitching rotation means nothing and that he just happened to have luck go his way with 16 games he won?

So to answer the first question I simply listed every pitcher the Rox faced and using WAR to established who for the particular team was number one, two, and so forth. I then matched this with the Rox pitcher and took the average over the season. Therefore if an average team had 5 starters who each pitched 32 games (and two more) then the average starting pitching value would be approximately 3.00. For the extreme example above (i.e. number one gets 36 starts) a value of 2.83 is the average starting pitching value. By averaging what your starter faced over a season you can determine if they faced more top of the rotation (i.e. number below 3.00) or faced the back end (i.e number higher than 3.00).

For instance Jimenez last year faced:
1, 1, 5, 5, 5, 5, 5, 2, 3, 1, 5, 3, 2, 2, 5, 3, 1, 3, 5, 3, 5, 4, 5, 5, 1, 1, 5, 4, 3, 1, 1, 3 (average 3.3)

As I said I went with WAR values to establish starter's rank. Wins can be deceiving and innings pitch can be skewed with late season trades or call ups. If a starter was not in the top 5 based on WAR I still used a 5 for that pitcher. Rarely do teams have a defined fifth starter. The spreadsheet below shows the results. Note: In the first week of the year I gave Webb a number one rating as he was slotted to be that had he not gotten hurt...the same for Myers with Philadelphia...he was the opening day starter. The rest of the matchups held true.

So while the theoretical best gives an average of 2.83, the Rox in 2009 was 2.99, and the opposing teams threw an average of 3.25. As the data shows Jimenez faced an average of 3.3, Marquis a 3.5, de la Rosa a 3.0, Hammel a 2.7, and Cook a 3.7. The data would suggest that over a long season the matchups rarely remain and that there are long stretches where our number one gets to face some fours and fives. It is interesting to note that the first three months indicated that our number three starter, de la Rosa, was getting the bulk of hard matchups having an average of 2.1 through June (perhaps that is why he started so slow?). Next week I will ponder the second question on whether it makes sense to not send your number one out on Game 1 and establish the pecking order differently.

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