Comments on Basement Dwellers: April 2007 Reds Review Part 1: Overview

Hey--yeah, I can't take credit for the idea. :) I...

2007-05-02T11:55:00.000-04:00

Hey--yeah, I can't take credit for the idea. :) I should have also given Dave Studeman at hat tip, as I would have never seen that stuff if he hadn't highlighted it in a column last season. I've been wanted to make one of those graphs every since. I'll try to do one for each monthly review this season, as I'm in love with the concept now.

As far as what is typical for bullpens, I haven't looked at this closely, but my guess is that good bullpens tend to be above-average, while bad bullpens tend to be below average. Here are the Reds' bullpen WPA's over the past several seasons (via fangraphs):
2006 -2.07 (~-4 wins)
2005 -1.57 (~-3 wins)
2004 -3.11 (~-6 wins)
2003 +3.76 (~+7-8 wins)
2002 +5.43 (~+11 wins!)

As far as how a bullpen with that bad an ERA could be only slightly negative on the season, it all has to do with the situation in which those runs were scored. For example, if the game is tied and win probability is about 50/50 in the 9th inning, and then the bullpen gives up 15 runs, you'll lose about 0.50 WPA. But if you're ahead in the 9th by one run, and suddenly your closer gives up 2 runs, you might lose close to 0.90 WPA.

So, perhaps, the Reds 'pen didn't do as much damage you might have expected them to do based on the average rate at which they allowed runs...

Differences between average performance (ERA, Runs Created, etc) and situational performance (WPA) probably get less substantial the longer the season progresses.

I'm just going to do RC vs. WPA (or ERA vs. WPA) in the hitting and pitching sections for now. Those day-by-day graphs take too long to put together to do it for each player! :D
-j

Ah, I see - credit to SoxWatch for the concept. I...

2007-05-02T11:37:00.000-04:00

Ah, I see - credit to SoxWatch for the concept. I hope we can look forward to graphs of individual WPA contributions in the detailed analyses to come. Don't burn yourself out though.

J, honestly - where do you get the ideas for these...

2007-05-02T11:31:00.000-04:00

J, honestly - where do you get the ideas for these concepts? That "cumulative WPA" segregated by hitters/relievers/starters is just beautiful.

For comparison on those performances by the different parts of the Reds, how would it divide out for a typical MLB or NL team? I wonder if a typical bullpen - not an exceptional one, just an average kind - would tend to have a higher aggregate WPA due to the higher leverage situations a bullpen is typically placed in.

I'm just trying to understand how the Reds bullpen, which for the month had the fourth worst relief ERA in baseball, came out the other side with only a slightly negative WPA. Does the average bullpen boast a significantly positive WPA?