WAR, projections, FIP and defense

[Bull]

Looking over player projections for 2026 and fWAR vs bWAR values from last year.  I know I'm probably late to the party on this, but I'm trying to figure out a few things.

1. ZiPS is based on FWAR which is fielding independent. Since several Cubs pitch to contact, their projections undervalue them. TorF? Is this an accurate premise to build off of?

2. The Cubs pitching staff is advantaged by their excellent defense, whether that is PCA running down Shota's gopher balls in the gaps, or Nico and Dansby picking it for Boyd and Cade.

3. Much of the value of Cubs pitchers throwing ground balls (or fly balls) is realized in Cubs defenders with fWAR. With bWAR, the value of Cubs defenders picking more ground balls that their pitchers threw is counted for both the Cubs defenders AND their pitchers receiving value credit. TorF?

4. If 1, 2, and 3 are true, why are Cubs pitchers' 2025 fWAR values, consistently lower than bWAR? Boyd Horton Rea fWAR 3.4, 2.2, 1.9 respectively. 2.5, 2.0, 1.5 bWAR. Shouldn't the bWAR be higher due to the Cubs elite defense. 

 

Somewhere along the line I'm getting something wrong. 

Edited February 2 by Bull

[Geographyhater8888]

bWAR exaggerates the impact of park factors relative to fWAR, so Cubs hitters had a relatively higher OPS+ than wRC+. The defensive calculations are different too so bWAR basically weighs the impact of Cubs defenders and Wrigley’s pitcher friendly conditions much more heavily than Fangraphs. The discrepancy between the positional bWAR and fWAR is an 8 win difference so they got all the credit for those defensive runs saved and pitching got very little from baseball reference. 
 

As far as projections go ZIPS always leans conservative. Cubs pitchers had a higher fWAR than bWAR in 2025. Are you asking why the projections are lower by ZIPS?

 

Edited February 2 by Geographyhater8888

[Bertz]

This is a good set of questions on a fairly complicated subject.  Some things I'll note:

- ZiPS calculates a players underlying numbers (Ks, BBs, HRs, etc.) and then calculates FIP and estimates ERA from there.  The fWAR you see on various player pages is based entirely on that projected FIP.  HOWEVER, when you read the big hefty ZiPS projection article it uses a variation of WAR that attempts to include contact quality.  Ben Brown is a great example, he's projected at 1.0 WAR above and 1.6 WAR on his player page

- This is a bit confusing and annoying, but the flip side would be every projection system on a player's page following different rules which would be even more confusing

- The Cubs' defense is stellar, but we have to take care to not double count that.  If the Cubs defense saves 50 runs in a season that's 0.30 runs of ERA.  So you can't give PCA/Swanson/Hoerner their defensive runs and then also give Boyd full credit for beating his FIP by 0.40 runs

- I do not use bWAR much.  I believe it takes a pitcher's ERA, strips out the impact of defense, and then gives the pitcher the rest of the credit.  I philosophically do not agree with this.  IMO there's far too much luck even in a full season for that to be a reasonable approach.  Over larger samples I'm less opposed (e.g. I'd use bWAR for Kyle Hendricks' full career but not for an individual season)

- The magnitude of the contact management stuff isn't huge on a team level.  The Cubs last year had a 3.81 ERA, 4.04 xERA, and matching 4.16 FIP/xFIP marks.  That xERA/xFIP gap is what you'd potentially consider the soft contact skill to be.  0.12 runs of ERA even over a full season is 20ish runs total.  Add in roster turnover and regression and the effect is small enough that it's not going to significantly move the needle.  I also don't blame someone for just throwing it out with the bathwater entirely

- I do not have the citation for this, it was in a chat years ago, but Dan Szymborski has said you need hundreds of innings to confidently say someone is a FIP beater.  It's basically a situation where it takes so long to establish that someone is a FIP beater, by the time you can say it definitively looking backwards you have to start worrying about whether the talent level will hold up looking forward

And then I know this is way too long already, but a few tangentially related thoughts on evaluating pitching:

- I tend to look at xFIP first when evaluating a pitcher and also give it the most weight.  It is focused on only the things a pitcher can control, and isn't an overengineered black box like BaseballProspectus' stats.And IMO 

- xERA is the ideal compliment to xFIP.  There is a good bit of luck to contact quality, so I do think xFIP carries a good bit more weight, but all of the reasonable counterarguments to xFIP are handled by xERA.  If you use xFIP and xERA as brackets you are almost certainly capturing the range of how a pitcher actually performed IMO

- This is a little reductive, but for the sake of nice round numbers half a run seems to be the extent to which someone can under or overperform their peripherals at a true talent level.  Anything more than that and you should credit/blame the defense or assume it'll smooth out with more time

[Bull]

25 minutes ago, Geographyhater8888 said:

bWAR exaggerates the impact of park factors relative to fWAR, so Cubs hitters had a relatively higher OPS+ than wRC+. The defensive calculations are different too so bWAR basically weighs the impact of Cubs defenders and Wrigley’s pitcher friendly conditions much more heavily than Fangraphs. The discrepancy between the positional bWAR and fWAR is an 8 win difference so they got all the credit for those defensive runs saved and pitching got very little from baseball reference. 
 

As far as projections go ZIPS always leans conservative. Cubs pitchers had a higher fWAR than bWAR in 2025. Are you asking why the projections are lower by ZIPS?

 

I’m asking, if fWAR is fielding independent, fip rather than RA9, then the Cubs pitchers should do better in bWAR, because they aren’t big strikeout guys. The opposite is true.

[Geographyhater8888]

1 hour ago, Bull said:

I’m asking, if fWAR is fielding independent, fip rather than RA9, then the Cubs pitchers should do better in bWAR, because they aren’t big strikeout guys. The opposite is true.

Because baseball reference exaggerates park factors and their defensive runs saved model for some reason really loves giving credit to cubs defenders (59 runs vs 34.5 defensive runs) and more than the pitchers despite their respectable runs per 9. Their OPS+ as a team was 116 and wRC+ was 110 because of the park factor. So I’d assume cubs pitchers get penalized a lot for that too. Fangraphs also gives pitchers 430/1000 total war in a season while BR only gives pitchers 410/1000. That’s the best I’ve got.

Edited February 2 by Geographyhater8888