Baseball Musings
Baseball Musings
August 17, 2007
Webb Gem

Brandon Webb pitches his third consecutive complete game shutout, extending his scoreless inning streak to 42 innings. Orel Hershiser's record is 59, so Webb still needs two more complete game shutouts to break the record. This was his best pitched game of the streak, allowing just two hits and one walk while striking out six.

Webb's ERA is now 2.63. That means the odds of him giving up a run in an inning is .29222 (2.63/9). That makes the probability of his getting another eighteen scoreless innings .00199. You could probably get a better estimate, however, if you figured out how often he actually gives up a run in an inning.

Update: Jay Jaffe points out I should use RA, not ERA, since unearned runs end streaks, too. In that case, the probability of a run in an inning is 0.3574, and the probability of 18 consecutive scoreless innings is .00035.

Update: Scott Segrin writes:

I looked up some numbers for Brandon Webb (which you must do - dividing his ERA by 9 only works if he pitched no multi-run innings). By my count, he has pitched 145 scoreless innings and 40 innings in which he gave up at least one run, making the chance that he gives up a run 0.2162. This translates into a probability of .01246 that he goes another eighteen scoreless. Granted, only a bit over 1%, but still over 6 times higher than your number.

Thanks Scott. A 1 in 80 chance makes much more sense.


Posted by David Pinto at 09:55 PM | Pitchers | TrackBack (0)
Comments

NERDS!

Posted by: Ogre at August 18, 2007 02:57 PM
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