Correlation between ERA and WHIP

[soccer10k]

I've heard people talk about it and understand the concept of it (i.e. if a guy lets a lot of runners on he's probably going to have a higher ERA and vice versa), but what I haven't been able to find are concrete numbers on it.

 

Is there a formula that calculates expected ERA based on WHIP (eERA = a * WHIP + b) or something along those lines?

 

Basically, if a guy has a 1.00 WHIP (or whatever number), about where do we expect his ERA to be?

[manbearcub]

http://vis.berkeley.edu/courses/cs294-10-fa07/wiki/images/b/ba/Whip_era.jpg

[Sammys Boombox]

http://vis.berkeley.edu/courses/cs294-10-fa07/wiki/images/b/ba/Whip_era.jpg

 

So one guy has a whip of about 1.7 and an ERA of about 3.50 while this other guy has a whip of 1.6 and an ERA close to 7.00. Cool.

 

Obviously there appears to be a pretty good linear fit to these statistics.

[Guest]

I thought that was a scene from Independence Day.

[Guest]

Anyone else?

[TruffleShuffle]

Anyone else?

 

personally i think it's really hard to get a reliable correlation. i'd rather have a guy with a 1.40 WHIP who walks 0.7 guys per inning and gives up 0.7 hits per inning, than a guy who never walks anybody but gives up 1.4 hits per inning. the guy who gives up more hits is going to give up significantly more runs because the walks are station to station advances whereas some of those hits will be for extra bases or guys can go 1st to 3rd, etc. there's also the matter of how much extra base power a guy tends to give up. much like OPS's major flaw being a point of OBP equaling a point of SLG, WHIP's big flaw is that a walk and a hit are each valued the same.

 

i'm sure there is a rough estimate but if you're looking for expected ERA, i wouldn't just use whip.

[Guest]

Anyone else?

The graph says it all. There's nothing else that needs to be said.

[mcgoobs]

Anyone else?

 

personally i think it's really hard to get a reliable correlation. i'd rather have a guy with a 1.40 WHIP who walks 0.7 guys per inning and gives up 0.7 hits per inning, than a guy who never walks anybody but gives up 1.4 hits per inning. the guy who gives up more hits is going to give up significantly more runs because the walks are station to station advances whereas some of those hits will be for extra bases or guys can go 1st to 3rd, etc. there's also the matter of how much extra base power a guy tends to give up. much like OPS's major flaw being a point of OBP equaling a point of SLG, WHIP's big flaw is that a walk and a hit are each valued the same.

 

i'm sure there is a rough estimate but if you're looking for expected ERA, i wouldn't just use whip.

 

I would guess that looking at OPS against would show a tighter correlation to ERA.