Over the Retrosheet Era, total Fielding Decisions for each of the three outfield positions were as follows:
At first glance, this looks a little curious. Why do left fielders and right fielders accumulate more fielding decisions than center fielders? What does this mean, exactly? Is a good defensive right fielder more valuable than a good defensive center fielder? Arguably. Should teams play their best defensive outfielder in right field rather than center field? Probably not.
The reason for this apparent anomaly is not because corner outfielders are better, or even necessarily more valuable, than center fielders. Rather, this is the result of two issues that are worth thinking about with respect to Player Won-Lost records. First, there is a wider range of fielding talent across corner outfielders than across center fielders, and, second (and somewhat related), there is a greater range of possible outcomes on balls hit to left or right field than on balls hit to center field.
The table below shows the number of plays in the 2007 American League (i.e., games played at AL ballparks) for which the various outfielders are the fielder of record (i.e., are the first fielder to touch the ball):
*“Singles” include batters reaching on error.
For simplicity, suppose that singles have a net fielding win value of -0.0364 and extra-base hits have a net fielding win value of -0.0625 (these are reasonably close to the average net win values for these plays in recent seasons).*
Let’s also normalize the above numbers to be per 100 plays.
*Base hits will likely not have the exact same value to all fields because of differences in baserunner advancement. The numbers here should therefore be thought of as illustrative, not definitive.
So, for example, left fielders allow 38.68 singles per 100 plays. At -0.0364 wins per play that works out to -1.41 wins for left fielders on singles allowed. Full numbers are shown in the table below.
|Net Wins on:
||Wins per Out
Let me walk through the numbers briefly. As noted above, left fielders allow 38.68 singles per 100 plays with a value of -0.0364 wins (0.0364 losses) per single, for a total of -1.4078 wins (1.4078 losses). Left fielders allow 16.35 extra-base hits per 100 plays with a value of -0.0625 wins per extra-base hit, for a total of -1.0218 wins on extra-base hits. Adding these together, left fielders accumulate approximately 2.43 losses per 100 plays. Since fielding wins and losses are set to be equal in the aggregate for every position by construction, this means that left fielders also accumulate 2.43 wins per 100 plays, which works out to 0.0540 wins per out by the left fielder.
Note what this shows. Plays made by the left fielder are worth more player decisions on average – 0.049 decisions per play*
– than plays made by right fielders – 0.046 – than plays made by center fielders – 0.041. This is true for two reasons. First, center fielders allow fewer extra-base hits than corner outfielders – 10.7 per 100 plays vs. 15.8 per 100 plays for corner outfielders, and extra-base hits have the highest value in terms of total player decisions per play. Second, center fielders allow fewer hits than corner outfielders – 48.6 per 100 plays vs. 54.0 per 100 plays – which makes outs to center field less valuable – because they’re more common – than outs to the corners. The overall result is that an average play made by a left fielder is worth about 19% more player decisions than an average play made by a center fielder, which is more than enough difference to offset the fact that center fielders were involved in 14% more plays than left fielders (in the 2007 American League).
*2.4295 wins plus 2.4295 losses equals 4.86 total decisions per 100 plays, or 0.0486 decisions per play.
The primary reason for this, I believe, is that there is a much wider range in the abilities of corner outfielders as compared to center fielders. Mathematically, this can be measured by looking at the standard deviation of winning percentages by corner outfielders. Over the Retrosheet Era, the standard deviation
of season-level winning percentages for center fielders (fielding only) is
5.1% for right fielders and
5.2% for left fielders. In other words, the spread in winning percentages for corner outfielders (which can be taken as an approximation of the spread in the fielding talent of corner outfielders) is approximately
13% greater than the spread in center-fielder winning percentages (fielding talent).
In words, virtually all center fielders are good fielders, whereas, while some corner outfielders are excellent fielders (e.g., Ichiro Suzuki
), others are notoriously bad fielders (e.g., Manny Ramirez
). The result is that the value of a corner outfielder who is capable of converting balls in play into outs and in preventing extra-base hits is greater than the value of a center fielder that can do the same, because such a corner outfielder is rarer. Curious, but I think it’s true.
All articles are written so that they pull data directly from the most recent version of the Player won-lost database. Hence, any numbers cited within these articles should automatically incorporate the most recent update to Player won-lost records. In some cases, however, the accompanying text may have been written based on previous versions of Player won-lost records. I apologize if this results in non-sensical text in any cases.
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