November 20, 2008

2009 Batter Projections

Not a lot to write today.

I have finished the work on my batter projections. There are 2447 projections currently available. Click here for an xls version or here for a csv version. I do need to finish filling in primary defensive position for many of the minor league players. I will repost the files when that is completed.

  • It includes all batters appearing in 2008 at Class A or higher.
  • For those batters, all levels that they played on in their career are included, including college.
  • Stats are park neutral. To find how a batter would do for a given team, that team's factors would need to be applied.
  • Also neutralized for level, including college, US minor leagues, and Japan.
  • Projection is then regressed to the highest level the batter appeared at
  • Also added an age adjustment

All these factors are empirically derived from comparing sets of batting data, described in detail in earlier posts.

Now I have 10 years of projections and actual performances to peruse, looking for any patterns, and analyzing the error distribution of actual data compared to the projections. This will allow me to give reliability scores and curves, like PECOTA's percentile breakdowns.

Probably this wekend I will post a list of the 2008 batters who most over or under achieved compared to the last projections, and are therefor the most likely to regress back towards the middle.

 

 

 

 

Tags: Projections

Discussion

6 Comments on "2009 Batter Projections"

#1

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Posted by jinaz, November 20, 2008 9:08 PM

Congrats on your release!
-j

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#2

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Posted by Aaron B., November 21, 2008 3:37 PM

Brian, these are awesome. Tango mentioned these earlier this year in a thread over at his blog, and I'm looking forward to poring over them.
Thanks for your work.

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#3

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Posted by j, November 21, 2008 7:31 PM

no varitek?

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#4

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Posted by Brian Cartwright, November 22, 2008 1:38 AM

I just updated the file, added RetroID for all players with MLB experience, and EliasID where I have it for the minor leaguers. Also added the missing Varitek record

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#5

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Posted by JMS, November 23, 2008 8:31 AM

How much does recency play into the projections? Jorge Posada is projected to hit 6 HRs in 2009. Is this a result of him only playing 51 games last year? Thanks.

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#6

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Posted by Brian Cartwright, November 23, 2008 10:45 AM

The playing time is based entirely on 2008. I have not yet done anything to project 2009 playing time. If you do your own playing time estimate, then take your estimated 2009 PAs, divided by the PAs I give, then multiply by my estimated counting stats.

Stat-wise, the projections are Marcel based. 2008 is weighted at 1.0, 2007 at 0.70, 2006 at 0.49, etc, each preceding season 0.7 times the last.

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