## Era-Neutral WAR: Leveling the playing field (sorry, Mark Teahen)

Jonathan Daniel

The way that FanGraphs calculates WAR has changed in recent years as more data have become available. But is this fair (or unfair) to modern players? I set out to find the answer.

One of the main criticisms of WAR by traditionalists is that no one really knows how to calculate it. I used to think this was true, until I discovered the world of wonder that is the FanGraphs Glossary. There, the entire process is explained, with links to other articles that go into greater detail. The equation for WAR (which can be found here) for position players is as follows:

WAR = wRAA + UZR* + BsR + PosA + RepL

*Use rSB + RPP for catchers.

There are a few complicating factors — the aforementioned calculations for catchers, the park adjustments for wRAA, and the reasoning for the positional and replacement-level adjustments — but as a whole, this seems pretty simple, right? Well, it is, but it hasn't always been.

See, 2002 was a big year for sabermetrics. That was the first season for which batted-ball data were available, which meant a lot of new stats could be created based off that. Two of these were UBR — which measures non-base-stealing elements of baserunning — and UZR — which measures fielding. For all player seasons from 2002 until the present, these have been the components of WAR.

But what was used for all years prior, you ask? Well, in lieu of UZR, TZ was implemented; because it is calculated retroactively from box scores and without batted ball data, TZ is less definitive than its replacement. There is not, in fact, a substitute for UBR in the previous years' equations.

So the main takeaway from this is that WAR from 2002 to 2013 is going to be a more accurate reflection of a player's ability than WAR from 1871 to 2001. What the question becomes (or what it became for me, at least) is this: How is this fair? Why should someone that plays in this era be judged differently than a player from the days of yore?

Being the justice-seeker (and, y'know, general loser) that I am, I decided to set things right. I looked at players, of whom there were 406, with at least 2000 plate appearances in the Batted Ball Era, and totaled up their career UBRs and UZRs*, along with their career RAR (Runs Above Replacement — WAR in run form) and their TZ from 2002 to 2013. I then calculated the career RAR for each player with TZ instead of UZR* and without UBR — in other words, the Era-Neutral RAR, or ENRAR.

*Again, using rSB + RPP for catchers.

What were the results? For most of the players, there wasn't a whole lot of change. The average RAR of the group was 208.55, and the average ENRAR was 209.59; the R² was .976, which means that there was a very strong correlation between the two.

This is not to say, however, that there were no outliers. Of the 406 players, 35 saw their career RAR increase or decrease by 50 runs or more; these players are reprinted below, that you may gaze upon them in wonder:

Name PA UBR Fld TZ RAR ENRAR Diff
Mike Lowell 4944 -28.7 -0.3 55 276.0 360.0 84
Pat Burrell 5428 -31.5 -43.6 2 187.1 264.2 77.1
Adam Dunn 7531 -16.0 -128.4 -69 232.9 308.3 75.4
Todd Helton 6706 -22.3 23.6 72 570.3 641.0 70.7
Ryan Howard 5018 -36.5 -23.4 10 206.3 276.2 69.9
Robinson Cano 5791 3.3 -27.6 45 360.4 429.7 69.3
Manny Ramirez 5059 -22.2 -115.1 -68 689.6 758.9 69.3
Lyle Overbay 5503 -11.5 2.3 59 116.5 184.7 68.2
Paul Konerko 7234 -63.5 -31.0 -35 262.9 322.4 59.5
Matt Kemp 3897 11.0 -68.3 2 200.3 259.6 59.3
David Ortiz 7022 -53.6 -4.3 0 407.2 465.1 57.9
Garret Anderson 4757 -5.5 -14.3 38 241.9 299.7 57.8
Adrian Gonzalez 5671 -29 36.9 65 308.8 365.9 57.1
Jermaine Dye 4368 -14.6 -103.2 -62 159.4 215.2 55.8
Yadier Molina 4601 -27.2 79.2 106 279.6 333.6 54
Jhonny Peralta 5680 -18.2 -2.6 32 222.8 275.6 52.8
Asdrubal Cabrera 3455 4.5 -44.3 13 126.3 179.1 52.8
Cliff Floyd 3116 -3.7 -28.4 19 241.9 293.0 51.1
Vladimir Guerrero 6015 -20.5 -17.2 13 579.7 630.4 50.7
Kevin Millar 4172 -30.1 -56.0 -36 91.1 141.2 50.1
David Wright 5945 12.1 -8.4 -49 496.7 444.0 -52.7
Hunter Pence 4474 13.3 22.4 -19 238.3 183.6 -54.7
Brian Roberts 5613 11.3 23.1 -24 284.5 226.1 -58.4
Rickie Weeks 4414 11.7 -49.0 -97 169.2 109.5 -59.7
Ryan Zimmerman 4943 14.1 29.8 -17 339.5 278.6 -60.9
Nick Punto 3505 17.9 85.1 41 146.7 84.7 -62
Orlando Cabrera 6405 25.2 21.9 -18 264.2 199.1 -65.1
Chase Utley 5671 29.9 101.7 65 549.1 482.5 -66.6
Alex Rios 5997 23.0 60.2 16 263.9 196.7 -67.2
Torii Hunter 7137 16.2 3.8 -49 421.9 352.9 -69
Brian Giles 4814 14.3 -29.9 -87 564.2 492.8 -71.4
Carl Crawford 6528 25.5 123.6 72 387.1 310.0 -77.1
Ben Zobrist 3824 10.4 55.8 -11 278.7 201.5 -77.2
Juan Pierre 7378 50.7 33.3 -4 236.7 148.7 -88
Brandon Phillips 5655 17.6 69.5 -7 263.7 169.6 -94.1

Some of the discrepancies (like those for Pierre, Utley, Ortiz, and Konerko) were primarily due to their UBR, while others (like those for Phillips, Zobrist, Cano, and Dunn) can be attributed to differences between UZR and TZ.

But this doesn't really tell us what we want to know, which is how much the players' WAR will change from its old figure (i.e. a percentage increase or decrease). To determine this, I divided their ENWARs by their WARs and subtracted 1, which gave me the percentage change. Again, most players only saw marginal changes, but some (mainly those with very little playing time) were greatly affected. Below, you'll find a table of all players that saw a change of 50% in their career RAR when adjusting for era:

Name PA UBR Fld TZ Diff RAR ENRAR Diff%
Angel Berroa 2751 6.4 -34.1 -17 10.7 3.8 14.5 281.58%
Jeremy Hermida 2261 -8.8 -15.4 11 35.2 18.2 53.4 193.41%
Michael Morse 2027 -19.6 -42.3 -21 40.9 25.5 66.4 160.39%
Jason Kubel 3707 -11.2 -54.5 -34 31.7 27.5 59.2 115.27%
Casey Kotchman 3412 -21.5 31.3 37 27.2 27.0 54.2 100.74%
Kosuke Fukudome 2276 -0.8 -8.7 32 41.5 45.3 86.8 91.61%
Dioner Navarro 2505 -21.5 -8.0 4 33.5 41.5 75.0 80.72%
John McDonald 2505 3.0 33.5 44 7.5 9.6 17.1 78.13%
Skip Schumaker 3043 1.1 -51.0 -27 22.9 32.3 55.2 70.90%
Garrett Atkins 3273 -4.4 -30.9 9 44.3 71.5 115.8 61.96%
Rick Ankiel 2021 2.0 -9.6 16 23.6 38.4 62.0 61.46%
Brady Clark 2154 0.9 -4.8 27 30.9 51.2 82.1 60.35%
Adam Lind 3408 -8.8 -17.9 3 29.7 50.4 80.1 58.93%
Lyle Overbay 5503 -11.5 2.3 59 68.2 116.5 184.7 58.54%
Rod Barajas 3642 -23.2 8.2 24 39.0 66.8 105.8 58.38%
Marcus Thames 2016 0.3 -18.7 -5 13.4 24.0 37.4 55.83%
Kevin Millar 4172 -30.1 -56.0 -36 50.1 91.1 141.2 54.99%
Wilson Betemit 2330 -6.5 -51.3 -44 13.8 26.1 39.9 52.87%
Alcides Escobar 2578 12.4 8.3 -7 -27.7 54.3 26.6 -51.01%
Alex Cora 2913 9.5 16.3 2 -23.8 42.7 18.9 -55.74%
Gordon Beckham 2475 4.7 2.5 -23 -30.2 52.6 22.4 -57.41%
Ty Wigginton 4949 -10.5 -86.1 -118 -21.4 35.0 13.6 -61.14%
Emilio Bonifacio 2299 17.5 -14.8 -21 -23.7 38.1 14.4 -62.20%
Ramon Vazquez 2190 4.9 -19.4 -39 -24.5 22.6 -1.9 -108.41%
Wes Helms 2770 -2.2 -30.7 -41 -8.1 5.3 -2.8 -152.83%
Mark Teahen 3171 3.9 -46.4 -89 -46.5 23.2 -23.3 -200.43%

(Note: players with negative career RAR were not included.)

Similar trends appeared, with players seeing baserunning (Millar, Bonifacio) or fielding (Atkins, Wigginton) affect their scores. The largest change, though, was by Teahen, as the title of this post might've suggested; his defense was valued so poorly by TZ (relative to UZR) that he went from a two-win player to a negative two-win player.

So, to reiterate, the change from TZ to UZR and UBR is definitely a good one — it gives us a much more valid view of a player's performance — but, when doing historical comparisons, the standards should be the same for everyone, even if it isn't beneficial. (Again, sorry, Teahen!)

. . .

All statistics courtesy of FanGraphs and Baseball-Reference.

Ryan Romano writes for Beyond the Box Score, the FanGraphs Community Blog, and Camden Chat that one time. Follow him on Twitter at @triple_r_ if you enjoy angry tweets about Maryland sports.

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