Weighted WAR: 2025 Update Part 2

Last time, we did a brief review of how the Weighted WAR system works, and also updated the top-100 lists for right field, left field, third base, and first base/DH to reflect the results of the 2025 season. Now, we’ll go over the remaining positions, as well as some numbers dealing with the current state of the top-100 lists as a whole.

The first update post opened with right field, the home of the player who had the best season in 2025. This time, let’s start with the home of the active player with the highest career rating: center field.

Weighted WAR: 2025 Update Part 1

Around this time last year, I posted a series of articles suggesting a variety of adjustments that can be made to Baseball Reference WAR (bWAR) for the purposes of historical comparison, and then constructed a player ranking system (Weighted WAR) based on the results. The modifications were discussed in conjunction with the releases of the Weighted WAR rankings at specific positions, as follows:

Peak weighting (introduction)

Schedule length (3B)

Positional classification (LF)

Timeline adjustment for minor league control and segregation (SS)

Timeline adjustment for expansion (2B)

Negative seasons (CF)

Negro League seasons (C)

Pitching value (1B/DH)

Uncounted factors (RF)

(Not all of these topics are actually adjustments. The positional classification piece merely clarifies how I prefer to break down players between positional lists, while pitching value and “uncounted factors” review things that are, well, uncounted in the Weighted WAR system.)

It’s been a year since these posts went up, and that means we have another baseball season to account for. As such, let’s go through the positional top 100 lists again – not in full, but through the lens of players who were active in 2025.

Weighted WAR: Uncounted Factors and Right Field Rankings

The Weighted WAR series to date has covered the weighting system, schedule length, positional classification, timelining (in two parts), negative seasons, Negro League play, and (uncounted) pitching value. With weighted WAR now completely introduced, it’s time to go over the things that the system does not consider which might reasonably be included in an all-time ranking. More specifically, we’ll discuss four factors: war credit, minor league credit, additional non-MLB play, and postseason play.

Weighted WAR: Pitching, DH, and First Base Rankings

So far in the weighted WAR series, we’ve discussed the weighting system, schedule length adjustments, positional classification, timelining (in two parts), negative seasons, and most recently how all of those adjustments apply to the Negro Leagues. With all that in mind, it’s time to cover the two positions for which I haven’t compiled WAR-based top 100 lists: DH and pitcher.

Weighted WAR: Negro Leagues and Catcher Rankings

So far in the Weighted WAR series, we’ve covered the weighting system, schedule length adjustments, positional classification, timelining (part 1 and part 2), and negative seasons. Now, having covered all of the adjustments we’re making to WAR, it’s time to go through all of them again.

MLB now recognizes Negro League statistics from 1920-48. (This is not the totality of segregated black baseball, and it’s possible more will be added to the official record at some point, but for now I’m limiting my analysis to the MLB-recognized seasons.) WAR totals are also available for these years, via Baseball Reference and other sources. In this case, despite bWAR being my usual metric, I’ve decided to use Seamheads WAR instead; my understanding is that B-R doesn’t use park adjustments for NeL seasons, and Seamheads does.

Weighted WAR: Negative Seasons and Center Field Rankings

In the discussion of weighted WAR, we’ve covered the weighting system, schedule length, and timelining (part 1 and part 2), plus an aside to touch on positional classification. Now, we’ll finish up the discussion of WAR adjustments with one more topic: negative seasons, or more specifically, the reasons that I discard negative seasons from the rankings.

To be clear up front, I understand why negative WAR scores exist and agree that they should. It is in fact possible that a player can perform poorly enough to expect that a minor league journeyman would do better. Negative WAR values are relevant in any number of contexts – evaluating a team’s overall performance, projecting production moving forward, and so on. I just don’t think they add anything useful to weighted WAR’s evaluation of the player’s career.

Weighted WAR: Timelining part 2 and Second Base Rankings

To this point in the weighted WAR series, we’ve introduced the weighting system, the schedule length adjustment, and the method for classifying players by position. Most recently, we looked at the top shortstops through the perspective of the timeline adjustment – in particular, the adjustments for segregation and minor league control.

In the timelining discussion, I mentioned performing a sanity check by examining the total number of top-100 players at each position who come from each decade. (More specifically, I classified each player by the season in which their median plate appearance occurred and broke those down by decade.) In general, the number of representatives from each decade increased over time, but there were two major exceptions to this. First, the 1940s trailed behind the ‘20s and ‘30s; this is easily explained by World War 2 cutting short the careers of many players from that decade.

The second anomaly was much more unexpected: the 1880s were significantly ahead of the 1890s. After considering this discrepancy, I decided to implement a third timeline adjustment, this time for league expansion.

Weighted WAR: Timelining (part 1) and Shortstop Rankings

So far in the weighted WAR series, we’ve introduced the weighting system and the schedule length adjustment, and most recently talked about positional classification of players. Now, we’ll shift back to the adjustments I’m making to WAR in this system, which means it’s time to discuss the elephant-sized landmine in the room: comparing players across eras, often referred to as “timelining.”

Weighted WAR: Positional Classification and Left Field Rankings

So far in the discussion of weighted WAR, we’ve explained the weighting system itself, as well as the first adjustment to the base WAR totals, schedule length. We’ve also examined the system’s ranking of the best third basemen ever. But as we continue exploring both the system itself and the rankings it produces, there’s a question that needs to be answered: What does it mean to rank, say, the best left fielders of all time? More specifically, are we ranking players based on their value in left field alone (which I’ll call the “positional purist” approach), or are we evaluating their entire careers and using some criteria to classify that career into one position (the “whole career” approach)?

Weighted WAR: Schedule Length Adjustment and Third Base Rankings

Resuming the discussion of the weighted WAR system, we start with (hopefully) the least controversial modification of the WAR totals from individual seasons: schedule length.

Schedule length is an obvious problem when comparing players across seasons. Fortunately, using estimates of wins provided by a player (e.g. WAR) allows for a fairly systematic approach here. If a player posts a 3-WAR season, it will have a much bigger impact on an average team over a 60-game schedule (improving winning percentage by .050) than over a 125-game schedule (.024) or a 160-game schedule (.019). But a straight-line adjustment doesn’t quite work, as the standings will generally have a wider spread after 60 games than after 160. What you’d want to do is estimate how much impact an individual win has on the standings at various schedule lengths.

Introducing Weighted WAR

The last several decades have seen a veritable explosion of baseball statistical analysis, both by fans and by actual MLB teams. One of the primary products of this effort has been Wins Above Replacement (WAR), the general estimate of the number of wins a particular player provided in comparison to a freely available substitute. The merits of WAR have been debated ad nauseam since its introduction, but its appeal is obvious; it combines all of a player’s contributions (or at least, all that we have measurements for) into a single number that allows direct comparisons between players on different teams, at different positions, or from different time periods. For all its faults, WAR at least serves as a reasonable estimate and a good place to begin discussion.

It is not, however, the end of the discussion. I have been experimenting with a series of adjustments to baseline WAR totals which I feel lead to a more reasonable overall rating of baseball players throughout history, and will be presenting both those adjustments and some of the results over a series of upcoming posts. The adjustment I started with is a method of combining peak and career value into one number.