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07-10-2011, 09:48 PM
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Originally Posted by Rhodes 81 View Post
here's what i don't get about this though. if the defense really played that big of a role in era then that would mean the brave's defense would have to be significantly better than that of the phillies to account for jurrjens' era to be better than any of the phillies pitchers because of it, yet the braves have committed 10 more errors this year than the phillies have.
The skill of the defense is only one aspect. I would say, based on what I've seen and the stats, that the Phillies and Braves are a push defensively.

The real issue with ERA is that once the ball leaves the pitchers hand, the resultant outcome is beyond his control. The difference between a routine ground ball out and a seeing-eye single may be no more than inches, and once there is a man on base, anything can happen.

Here's an example.

Pitcher A has two outs and the bases are empty. Pitcher A makes a good pitch, which the batter hits on the ground toward the gap between the SS and the 3B. Fortunately for pitcher A, his 3B was shaded close enough that he was able to field the ball and throw out the runner at first. Inning over.

Pitcher B has two outs and the bases are empty. Pitcher B makes a good pitch, which the batter hits on the ground toward the gap between the SS and the 3B. Unfortunately for pitcher B, his 3B was shaded toward the line rendering him unable to make the play. Now there is a man on. Pitcher B still has the chance pitch his way out of the jam, but as you can see, he is in the jam in the first place because of something that was beyond his control. This is the inherent problem with ERA.

You can refer to this as whatever you'd like. Luck, randomness, whatever. The point is, once the pitcher makes his pitch, there are numerous things that can occur for which he has no control.

This is not a problem for DIPS.

also can't luck play a role in any statistic?
To some degree, I suppose. The point is to create better statistics by mitigating the effects of luck to the greatest extent. ERA is better than Wins and it's certainly better than having no metric at all, but there are stats that are better than ERA, hence why I pay little attention to it.

i can understand the ballpark argument because it's a lot easier to hit a home run in citizen's bank than it is at turner field, but at the same time i'd say it's easier to hit singles and doubles at turner.

CBP is definitely a hitter's park, while Turner Field is a bit of a pitcher's park. Turner field looks like it inflates triples, especially for left handers, but that's about it.

i understand era isn't the end all be all and there are other statistics that more accurately represent how well a pitcher can get people out without putting the ball in play or whatever, but if the pitcher's job is to not let the other team score, and jurrjens does that better than anyone else, how is he not the best pitcher?
Because he hasn't. A pitcher's job is to prevent runs from being scored, but he does that by making pitches that the batter is either unable to hit or unable to make good contact with. Roy Halladay has done the best job at putting batters in a position to make outs. What happens once the ball is in play is not up to him.

i guess that's the part that doesn't make sense to me. i really don't care if every single out is a ground out if it stops the other team from scoring. maybe that's just me though.
Strikeouts have a higher value than any other possible out because they don't put the ball in play, thus removing the possibility that the defense makes a mistake, the batter gets lucky or the runner beats the throw.

Originally Posted by Rhodes 81 View Post
also how exactly are defense independent stats determined?
FIP: ((13*HR)+(3*(BB+HBP-IBB))-(2*K))/IP + X. The X is simply a number that correlates FIP to an ERA scale to make it easier to understand.

xFIP is calculated the same way FIP is calculated except xFIP assumes a 10.6% HR/FB rate for all pitchers. Here's an explanation for why: Link.

The other two major stats, tRA and SIERA, are calculated with similar formulas.

does someone just decide how good a team's defense is and factor that into some formula or does it just subtract any out where the ball was put in play?
Team defense ratings would typically be based on UZR. UZR is the best defensive metric there is, but it isn't perfect and it only goes back about a decade, making it impossible to use retroactively. Here's an explanation of how UZR is calculated:

Originally Posted by Korean Devil 23 View Post
They provide a completely different way of analyzing the game. The problem is when people try to use them as a replacement for traditional stats all together.
Why would that be a problem? Everything that is described by traditional statistics is described by Sabremetrics, only more accurately. You aren't losing any information. The only argument for traditional stats is just that, tradition.

Last edited by Yoshimitsu: 07-10-2011 at 10:00 PM.
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