As of February, 2019, users of this website are able to make their own choices of positional averages to be used in evaluating player values. A full discussion of positional averages and other aspects of player evaluation using Player won-lost records can be found in a 50-page PDF essay which I have written, Comparing Players Using Player Won-Lost Records.

Player won-lost records are divided into three factors for which distinct positional averages are calculated: offensive player won-lost records, fielding player won-lost records, and pitching player won-lost records.

Offense

Distinct positional averages will be applied to offensive performance based on the fielding position of the player at the time he was batting. Positional averages will be calculated as a weighted average of four possible options using weights chosen by the user.

(1) 0.500 - i.e., all positions are treated equally.

(2) One-year positional averages. Positional averages will be calculated based on offensive performance by position within the season of interest.

(3) Nine-year positional averages. Positional averages will be calculated based on offensive performance by position within the season of interest as well as the four seasons immediately before and immediately after the season of interest.

(4) Long-run positional averages. Positional averages will be calculated based on offensive performance by position across all seasons for which Player won-lost records have been calculated.

In the past, I have chose option (2). In discussions - mostly online - this choice is somewhat controversial. I want to (a) be open-minded about issues of opinion - and one's choice of positional average is - while (b) trying to maximize the acceptance of the objective core of Player won-lost records - the wins and the losses. Hence, I have decided to allow users to choose their own positional averages. I don't want anybody to reject Player won-lost records because of my choice of positional average and I don't want debates about positional averages to get in the way of understanding the "objective truths" that Player won-lost records reveal via player wins and player losses.

On any page for which positional averages are presented or used in the underlying calculations, there will be boxes in which the user can enter any numbers desired associated with the four positional average options described above. Positional averages will then be calculated as a weighted average of the choices based on the numbers entered.

For example, entering values of 1, 2, 3, and 4 for options (1), (2), and (3), (4), respectively, would calculate a weighted positional average equal to (1/10) option 1 (10 = 1 + 2 + 3 + 4), (2/10) option 2, (3/10) option 3, and (4/10) option 4.

If the user does not enter anything, the default positional average weights options (2), (3), and (4) equally: (1/3) Option 2, (1/3) Option 3, and (1/3) Option 4.

Fielding

Positional averages for fielding are always equal to 0.500 for all positions for all seasons by construction. Differences between positions are reflected in the offensive positional average(s) chosen by the user.

Pitching

My player stat pages allow for different positional averages for starting versus relief pitcher if desired.

I believe that there are three possible ways to calculate positional averages for pitchers.

(1) Pitching is pitching: the positional average is 0.500 for all pitchers for all seasons by construction.

(2) Starting pitchers and relief pitchers should have different positional averages, which should be calculated empirically each season. That is, in 2018, the overall winning percentage for starting pitchers (excluding their offense) was 0.497; the overall winning percentage for relief pitchers (again, only on defense) was 0.504. Those are your positional averages for 2018.

(3) Starting pitchers and relief pitchers should, indeed, have different positional averages, but option (2) assumes that the pool of starting pitchers and the pool of relief pitchers are equal. What we should do, instead, is focus on pitchers who pitched as both starters and relievers. Doing this produces positional averages for 2018 of 0.487 for starting pitchers and 0.518 for relief pitchers.

In the past, I have chose option (3). In keeping with my general decision to allow users to choose positional averages, I have extended this to include allowing users to choose from among these three options for pitchers. Enter any numbers desired in the boxes associated with these three options and positional averages for pitchers will be calculated as a weighted average of the choices based on the numbers entered.

For example, entering values of 1, 2, and 3 for options (1), (2), and (3), respectively, would calculate a weighted positional average for pitchers equal to (1/6) option 1 (6 = 1 + 2 + 3), (2/6) option 2, and (3/6) option 3.

If the user does not enter anything, the default positional average weights the three options equally: (1/3) Option 1, (1/3) Option 2, and (1/3) Option 3. The multi-year user weights described above with respect to offensive positional averages will also be applied to pitchers. That is, if one chose to use 9-year averages for offensive positional averages, pitcher positional averages would also be calculated based on 9-year averages.

Overall, then, the default weights on most pages on the website will be equal weights to options (2), (3), and (4) for offensive positional averages (1-year, 9-year, and long-run) and equal weights to options (1), (2), and (3) for starting vs. relief pitching positional averages (0.500, empirical, and based on pitchers who do both). To replicate the weights used in my two books, Player Won-Lost Records in Baseball: Measuring Performance in Context and Baseball Player Won-Lost Records: 150 Players, 50 Years, one would choose option (2) for offensive positional averages (one-year average) and option (3) for pitchers (averages based on pitchers who started and relieved within the same season), while setting all other weights equal to zero.

Article last updated: August 11, 2019



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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