NERP and Catcher Defense

Started a proper scrape and now -3 looks right but +2 looks low...I guess earlier results were due to small sample size or some artifact specific to my teams

Here's what I have now after analyzing for 790 catchers. att=SB attempts against per season (640 hitting PA)

arm % att
-5 61 46
-4 63 62
-3 65 82
-2 66 100
-1 68 125
+0 72 152
+1 73 162
+2 74 236

All from $80 no DH leagues but no attempts to normalize for WHIP or hold. Your estimates were pretty close other than +2.

Iconic Catcher ~dNERP
J. Gibson - 3(-3)e2, T-6(pb-6) -1.32 dNERP
M. Piazza '97 - 4(+1)e6,T-10(pb-2) -4.16 dNERP
J. Mauer '09 - 1(-3)e1,T-4(pb-4) 2.52 dNERP
R. Bresnahan - 1(-2)e13, T-15(pb-14) -3.26 dNERP
B. Mackey - 1(-4)e1, T-5(pb-1) 3.24 dNERP
C. Zimmer - 2(0)e7, T-13(pb-14) -4.27 dNERP
M. Nokes - 3(+2)e2, T-5(pb-3) -2.46 dNERP
J. Kling - 1(0)e7, T-12(pb-4) -0.27 dNERP
J. Clements - 4(+2)e7, T-15(pb-12) -7.96 dNERP
J. Lucroy - 1(0)e1, T-4(pb-2) 1.89 dNERP
J. Bench - 1(-4)e7, T-11(pb-3) 1.44 dNERP
I. Rodriguez - 1(-5)e1, T-12(pb-0) 3.47 dNERP
C. Johnson - 1(-4)e0, T-1(pb-0) 3.85 dNERP

- with a static 70% success rate--- i wanted to power up the good arms a little so had the newer SB attempts for each each arm. MaxPower's data shows that climbing success rate, that would help alot. Ideas for what to punch in for each arm? ~1% success decrease with each arm increment improvement?

- pb has a TON of impact, like with my boy C. Zimmer. Explains his price better than ever. Not many catchers have the high pb-rating, so didn't post a great defender with lower pb becauase many don't exist. Errors are powerful which I don't love, but maybe that's right.

But wait.
If we assume you need a greater than 70% success rate to get an overall benefit from a stolen base, that implies that SB rate equal to 70% is neutral with no benefit to either team.

The overall gain in runs for a season would be:

A (successful SB) times value of successful SB

-minus-

B (Caught stealing) times value of CST

As long as A/(A+B) is 70%, then it shouldn't matter how big A and B are.

Yes, the success ratio improves a little for poorer arms but we really should only be counting the number of successful attempts above the 70% threshold

If a +1 arm gives 73% success on 162 attempts, that's only 3% above the neutral 70% level which equates to 5 "free" SB per season.

That's less than the number of "free" bases you give up with a bad balk or WP rating.

Yup catcher arms are relatively unimportant because most managers run into too many outs and the ones who don't generally aren't swiping that many bags. On top of that, as childswmc noted earlier, even with lower CS rates, the weaker arms are still generating more outs in absolute terms, which is valuable in itself in terms of reducing opposing PA.

But wait.
If we assume you need a greater than 70% success rate to get an overall benefit from a stolen base, that implies that SB rate equal to 70% is neutral with no benefit to either team.

...

If a +1 arm gives 73% success on 162 attempts, that's only 3% above the neutral 70% level which equates to 5 "free" SB per season.

That's less than the number of "free" bases you give up with a bad balk or WP rating.

If I understand your first point correctly labratory, I don't think it's quite like that. I'm using berce's Offense vs Defense NERP formula (including the SB part). I'd never really used the SB part or looked to closely but I'm just using this for a catcher's season (pro-rated to the 216 PA that all DiamondDope/NERP is tied to)

(TB * .318) + ((BB+HBP-CS-GIDP) * .333) + (H * .25) + (SB * .2) - (AB * .085) --- this works out to 0.624765478% success rate for "break-even"

I'm just assuming a flat 70% SB success rate against all Catchers. It's what Catcher's are facing as a success rate for the SB attempts against them.

This is the more updated NERP value from arms
(-5) T-10 ---- -1.14 NERP
(-4) T-10 ---- -0.92 NERP
(-3) T-10 ---- -0.66 NERP
(-2) T-10 ---- -0.36 NERP
(-1) T-10 ---- 0.00 NERP
(0) T-10 ---- 0.43 NERP
(+1) T-10 ---- .94 NERP
(+2) T-10 ---- 1.58 NERP
(+3) T-10 ---- 2.34 NERP

**labratory and MaxPower's comments about the ATG environment and outs is fascinating and something I'm probably out-of-date on. I LOVE circular lineups and not giving away outs but have always liked a SB Has ATG pretty univerally moved to a place where offenses are such battle-cruisers that a hyper tight "manufacturing" team that pitches its butt off and scores 800+ runs is just woefully behind when every other team scores....1000? I know strat enough and its always had those leagues sometime, but my point is, I'd think allowing MORE advantageous RBI situations would be less relevant in crazy run-scoring environments? ***I do believe in circular lineup benefit outside of "scoring" in an inning, but stealing bases an extra bag a game (+160!) at a 70% clip is pretty advantageous in ATG-X right?

**I suppose I have NOTHING factored in for the increase in "outs" that more attempts from "bad" arms brings. Hopefully that doesn't mar this as research looking for particular evidence, but I wanted some increase in value with better arms of course. So I started there in the NERP formula. Pro-rating to 108/216 ala DiamondDope seemed essential for the "yearly" SB against estimates. I don't really know how to work in "outs" from extra SB attempts or the runs prevented from getting those outs yet----I have those numbers, just don't know how to fit them into the NERP formula as they're not just "CS," plus the Runs per Game prevented from those outs. IDK how to get that into NERP currently.

For some reason I thought Pelletier on catcher defense had already been linked but if not: https://forum-365.strat-o-matic.com/com ... b1c8243ace

If you use his arm formula you don't have to worry about adjusting for the extra outs as it's all included, as is the effect on holds.

(I guess it's not technically a formula but it gives you the guideposts for the value of each arm in a neutral environment, and you can fit a formula to that.)

great stuff

**labratory and MaxPower's comments about the ATG environment and outs is fascinating

typical reaction I have too

I LOVE circular lineups and not giving away outs but have always liked a SB

my tendency as well

Has ATG pretty univerally moved to a place where offenses are such battle-cruisers that a hyper tight "manufacturing" team that pitches its butt off and scores 800+ runs is just woefully behind when every other team scores....1000?

I dunno...I still have success with extreme smallball doing the 800 runs+/-, great pitching, and 200-300 SBs. But you have to go all in and make it non-linear.

I have those numbers, just don't know how to fit them into the NERP formula as they're not just "CS," plus the Runs per Game prevented from those outs. IDK how to get that into NERP currently.

Indeed that is the challenge representing a non-linear relationship with a linear representation. Same as in nature. So we choose the boundaries and zoom in close enough to make it look like something we can represent and do it for multiple domains.
cool stuff nels and all.

In Marc P's earlier post he said that holding a runner changes the middle infielder from a SS-1 to a SS-4.
I thought the effect of holding was an increase from SS-1 to SS-2. Can anyone confirm if Marc is correct?


"And the impact of not holding a runner is huge: holding a runner has an impact on the defensive charts, a ss-1 (or a 2b-1) becomes basically a ss-4 (or a 2nd-4) but with still double-plays capabilities. Without holding the runner, the defensive player gets restored to his ss-1. "