Friday, April 08, 2005

Friday Morning Figures

Today we begin what we hope is a weekly feature here at Nats Blog: ERV scoring totals for the Nats. As explained here, ERV scoring measures the amount of runs each player has contributed to (or detracted from) the Nats success by comparing how that player improved or reduced the Nats expected runs each time he came to the plate, made or failed to make a play in the field, stole a base, faced a batter, etc.

For example, look at Brad Wilkerson's line. His smoking bat has produce over 4 more runs than the average in the past three games, but his fielding (the error yesterday that plated one run for the Phils) has cost them 0.81 runs and his baserunning has cost them 0.64 runs. Still, he has an impressive 2.57 overall runs contributed to the Nats, and clearly leads the team. In contrast, Guzman has cost the Nats 3.36 runs with his anemic bat, essentially nullifying Wilkerson's success. (For reference, the average team scores about 0.54 runs per inning, or about 4.8 runs per game. The RV figures here start from this average).

For pitchers, the data is expressed from the Nats perspective, so a positive number is good -- think of it as runs saved versus runs given away. For example, Luis Ayala has prevented 2.67 runs so far for the Nats, i.e. allowed 2.67 runs less than the average for the situations when he has pitched. Livan's poor outing puts him at the bottom, with over 4 runs given to the opponents. Note that these figures necessarily exclude errors and great fielding plays from their totals, as well as good baserunning by the opponents (except for steals, which are set out in the Running column for pitchers). So it gives you a relatively "pure" evaluation of the pitcher's performance.

Note that the scoring here is not entirely objective -- I have used my judgment about whether a fielding play was a great play, and also have deviated from the official scorer on occasion (e.g., I scored David Bell's dropped bunt popup yesterday an error (i.e. I assigned a portion of the RV to Bell's fielding rather than the batter), where the scorer said it was a hit -- both Phillies announcers agreed it should have been an error). My standards are pretty high for great plays, and I recognize them sparingly. I'm working on a post about an idea to make the judgments more objective.

This whole system is very much a work in progress, and comments are welcome. If interested, send an email to natsblog@gmail.com and I will send you the Excel workbook I am using to follow the season. If you are a geek like me, it's a lot of fun to chart a game with it.


Name PA Batting Fielding Running Total Tot/PA
WilkersonB 15 4.02 (0.81) (0.64) 2.57 0.171
CastillaV 14 1.80 0.74 (0.90) 1.65 0.118
VidroJ 15 0.85 0.00 0.00 0.85 0.056
GuillenJ 15 1.31 0.00 (0.73) 0.58 0.039
JohnsonN 12 1.39 (1.06) 0.00 0.33 0.027
HernandezL 2 (0.07) 0.00 0.00 (0.07) (0.036)
LoaizaE 2 (0.81) 0.64 0.00 (0.17) (0.086)
ChurchR 1 (0.17) 0.00 0.00 (0.17) (0.173)
SledgeT 10 (0.30) 0.00 0.00 (0.30) (0.030)
SchneiderB 13 (0.20) (0.25) 0.00 (0.45) (0.035)
DavisJ 5 (0.63) 0.00 0.09 (0.54) (0.108)
BlancoT 2 (0.55) 0.00 0.00 (0.55) (0.275)
CorderoW 4 (1.68) 0.00 0.00 (1.68) (0.419)
GuzmanC 15 (3.36) 0.00 0.00 (3.36) (0.224)


Pitchers BFP Pitching Running Total Tot/BFP
AyalaL 7 2.67 0.00 2.67 0.381
CorderoC 11 1.61 0.00 1.61 0.147
HorganJ 8 1.06 0.00 1.06 0.133
DayZ 23 0.11 0.00 0.11 0.005
OhkaT 0 0.00 0.00 0.00 #DIV/0!
TuckerT 1 (0.13) 0.00 (0.13) (0.133)
LoaizaE 29 (0.26) 0.00 (0.26) (0.009)
OsunaA 8 (0.35) 0.00 (0.35) (0.044)
EischenJ 7 (0.52) 0.00 (0.52) (0.074)
HernandezL 24 (4.02) (0.16) (4.18) (0.174)

2 Comments:

At 11:47 AM, Blogger Yuda said...

I'm glad you guys are doing this -- I was going to do it myself but now I don't have to.

Although I suppose this opens up time for me to track another team, maybe the Phils, for comparative purposes.

One question, though -- are you following the official scorer's decisions or making all the judgements yourself? Personally, I'd have penalized Vinny for the muffed line drive in the first game, although the scorer called it a single.

 
At 11:52 AM, Blogger SuperNoVa said...

DM-

Fixed, and I hope our conversation resolved the HTML issues.

Yuda-

Officially scoring decisions only - I can see your argument, but it's easier to go based on an established/verifiable source.

 

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