Saturday, April 08, 2006

ERV Boxscore Guide

New reader Bote Man requested a guide to the ERV Boxscores, so, within the limits of my meager graphic skills, I put together the image at right to help explain what the various headings on the box score mean. (Note: I didn't put it on the graphic, but PA is Plate Appearances and BFP is Batters Faced by the pitcher.)

Also, I'll explain here the new scoring rules I'm using. Last year I tried to judge great plays and screw-ups, not just official scoring errors, but that proved to be too much work. This year I am following the official scorer, and not trying to judge great plays. But I have implemented a new baserunning and fielding system.

Using the baserunning data compiled by Dan Fox, I've come up with rules as to who gets the credit when a runner takes an extra base. Where the data shows a runner advances more than 50% of the time, the batter gets the credit for that extra base. For times where it's less than 50%, the runner gets the credit (or the debit if they fail to advance when 50% of runners would have.) The outfielder who fields the ball gets a corresponding debit/credit for the runner's.

Here are the rules:

Single, 1st to 3rd -- Runner Credit every time
Single, 2nd to Home -- Batter Credit every time, except Single to Left or Right with no outs.
Double, 1st to Home -- Runner Credit on doubles to left and right, batter credit on doubles to center.
Sac Fly, runner scores-- Batter Credit every time
Sac Fly, runner to 3rd -- Runner Credit except on RF flies.
Sac Fly, runner to 2nd -- Runner Credit

I am also working on a system to give credit on routine plays like grounders and line drives, but I haven't implemented that yet.

The other change is the calculation of ERV Wins and Losses. I start with the winning margin base on Win Value adjusted runs (in the upper right corner of the boxscore). For the ERV Win, I look for all player or players who have a total WV above the winning margin. They share in the Win, in a proportion equal to their WV compared with the others. The logic behind this is if these players had played only an average game (0.00 WV), the team would have lost the game. If more than three players meet this criteria, the Win is given to the team.

If no player has a WV above the margin, then you start with the highest WV and keep adding the next highest until you are above the margin. the apportion the Win accordingly. Again, if it takes 4 or more players to reach the margin, nobody gets the Win.

For the ERV Loss, you follow the same procedure but use those with the most negative WV instead of the highest. If a player has a positive WV, he cannot get the loss, and vice versa.

UPDATE: I've decided to make ERV Wins and Losses simple. For the winning team, the player with the highest WV gets the ERV Win. For the losing team, lowest WV gets the ERV Loss. We'll see how that works over the season.

Note also that I publish the "Three Most Valuable Plays" with each boxscore. These are simply the individual events that had the highest absolute Win Value (i.e. positive or negative). The almost always indicate the points in the game that were most critical to the win or loss. For comparison purposes, a solo home run in the bottom of the ninth of a tie game would have a WV of around 6.0, meaning that run is worth 6 times the average run.


At 11:20 PM, Blogger Bote Man said...

Thanx for the effort! I award you a 100RV.

Now I must digest the runners' criteria that you just posted.


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