The Tiger WPA Blog

Studes, when I try to use the WPA spreadsheet to book a game, it often troubles me to properly split WP changes to pitchers and fielders, and on the offensive end, to hitters and runners. Is there a guide or a rule of thumb?

And is it possible to modify the spreadsheet so that we’d be able to credit more than just one offensive player/fielder in a play. I think it would be useful when it comes to breaking down a double play or any play that involves a tag out, in which more than one fielders should be credited.

We’ve played with some guidelines on this site before.  Check out this URL for some comments:

http://www.baseballgraphs.com/main/index.php/site/article/wpa_updates/

Regarding baserunning and such, I think the best thing to do is enter the play as two (or more) plays.  In general, this will allow you to handle the “what if” scenarios of some plays.  For instance, batter hits double and runner is thrown out at home can be entered as two plays.  If, in your opinion, the runner should have scored, enter the play as is the run was scored.  Then, add another play in which you take the run away and add an out, and credit that entirely to the baserunner.

In those cases, I just put “no one” as the player on the opposing team.

There are a lot of judgment calls to be made.  Probably what I should do is build an online guide for different situations.

I’ve been tracking WPA for the Braves this year, and I’d say I’ve seen roughly 75% of the plays and tried to credit players somewhat for fielding and baserunning.

The guideline I’ve been using for fielding is to only give/take credit from the fielder if the play was unusually good or bad.  I assign some percentage based on that, and hopefully it works out okay. 

Obviously I have trouble giving players credit for exceptionally good plays without watching all of every game, but I do my best.

I’m trying to make weekly posts (daily seems too ambitious, at least while I’m trying to graduate) at <http://www.jfwiii.net/braveswpa>, if you want to see what I’ve done.