is ERA+ a legit stat anyomre? check this

[Blackout]

http://www.baseball-reference.com/teams/PHI/2012.shtml

Halladay: 4.40 era = 91 ERA+

David Herndan: 4.70 era = 90 ERA+

Chad Qualls: 4.60 ERA = 88 ERA+


what is going on here?

[Joltin' Joe]

ERA+ is park adjusted thus it depends on which park the pitchers pitched on the road.

[brett]

ERA+ is park adjusted thus it depends on which park the pitchers pitched on the road.

This is a fairly recent change. A pitcher used to get the team's entire scoring environment. I am not sure they have gone back and done this for all seasons. If they do that, they might also adjust by home field edge (roughly 7-9% fewer runs allowed on average at home than on the road I think) and even by inning which could bring relievers down and starters up.

Everyone keep in mind that ERA+ is not a linear measure of run prevention. A 200 ERA+ only saves twice the runs on average as a 133 ERA+, and even less for starters because the average starter allows about 110%

[JDanger]

This is a fairly recent change. A pitcher used to get the team's entire scoring environment. I am not sure they have gone back and done this for all seasons. If they do that, they might also adjust by home field edge (roughly 7-9% fewer runs allowed on average at home than on the road I think) and even by inning which could bring relievers down and starters up.

The custom park factors go back until 1918. I've never read anything about a home-field advantage adjustment, but it's certainly an interesting idea.

http://www.baseball-reference.com/about/war_explained_pitch.shtml