What Are The Odds: Brandon Webb

On Wednesday night Brandon Webb will continue his assault on Orel Hershiser's 59 inning scoreless streak. To this point, he has hurled 42 consecutive shutout innings, including complete game shutouts in his last three starts.

It seems doable- Webb is only 18 innings away from breaking the record, which is two more CG shutouts. But how realistic is it that he'll actually get there?

First, let's see how unlikely it was for him to make it this far. Before the streak started, Webb had pitched 144 innings and allowed at least one run in 41 of them, or about 28%. Here are the chances that he would reach the following milestones:

Last week I did this same exercise for Bobby Jenks (whose streak ended at 41 batters on Monday night). Jenks' streak was actually less likely (1 in 2,243,780), since he only gets about 70% of hitters out, while Webb pitches a scoreless inning about 72% of the time- that 2% actually makes a big difference in a streak this long.

Here are the odds that Webb would have had a streak of this length at any point thus far this year (this time using current stats of 185 innings, allowing runs in 41 of them, 22%):

I was surprised by how often he would be expected to pitch 20 scoreless innings, but then again pitching a scoreless inning 78% of the time is a very high rate. 30 innings is when it starts to get real tough, and obviously his current streak is extremely impressive.

So, will he break the record? Well, if we only look at his scoreless inning % (78%) and the number of innings he has left (18), we'd be looking at about a 1 in 87 chance. But it's not quite that simple. First of all, Webb is obviously pitching better right now than he has been over the course of the entire season- this factor brings his number up to 81%.

The average NL team scores 4.62 runs a game. On Wednesday night, Webb will be facing the Brewers. Milwaukee plays in a neutral park, and averages 4.75 runs per game. In Arizona, which is a hitters park, they'd be expected to score about 5.08 R/G, 10% above league average. So we'd expect Webb to pitch a scoreless inning against the Brewers in Arizona 76% of the time- and pitch nine scoreless innings about 8.5% of the time, or once every 12 starts.

So shutting out Milwaukee is going to be tough. But if he can do that, he's got the hard part out of the way, as his next start would come in San Diego next week. This is the perfect combination for Webb (or any pitcher, really)- a terrible offense in an extreme pitchers park. At home this year the Padres have averaged 3.91 R/G, 15.5% below league average. This brings Webb's scoreless inning % to about 84%. So the he has about a 21% chance of shutting out SD; about 1 in 5.

But what we are really interested in, is how often Webb will pitch a shutout in both of these games, and break the record. That number is 1.8%, or about 1 in 57. Which just shows how amazing this streak really was.

All stats taken from Baseball Reference. Pictures taken from here and here.