NERP and Catcher Defense

Hello All!

I've been working on formulas for player value the last few years and the last thing I've been avoiding is translating catcher defense to "value," or NERP. NERP was added on DiamondDope years ago and can let Offense and Defense work together. So a player's offensive NERP (shown on DiamondDope) and Defensive NERP (on Berce's PDF) can get pretty close to a card's NERP. Just need a Baserunning/Stealing NERP adjustor, arm for OFers, INJ *multiplier, clutch hits, Ks, etc.

But catcher defense, for the Range, Arm, E-rating, t-rating and pb-rating are a blank in my database. For context a 1e8 at SS provide 7.2 NERP whereas a terrible 4(+1)e12/DH guy is probably like -8.5. Just add that into NERP via DiamondDope and value!

Does anyone have any formula or estimate for any part of catcher defense in NERP?

Catchers have 3 rolls on the x-chart per pitchers card (same as 3B and CF) so that's 27 x-roll checks on defense by the time they rack up 216 PAs. So about 81 a season? Again, same as CF and 3B. I see talk of pb ratings that are kind refreshing my memory in a recent post. Still hazy. pb rolls come up....once every 40 defensive rolls (with runners on base?) ?

So
-Range NERP (same x-rolls per 108/216 as 3B and CF)
-Arm NERP (can estimate from just attempts and % gained etc---already have SB ratings)
-e rating NERP
-pb-rating NERP
-T-Rating NERP

Any of these parts is a huge start on the others.

Thank you


Berce PDF: http://www.mfooz.com/bblog/wp-content/u ... efense.pdf
GOAT DiamondDope: http://diamonddope.com/card_reader.cfm

Here is what I have from past dinking around:

POS W/S W/G P/P P/F PO FO G1 G2 G3
C1 5% 15% 5% 10% 25% 20% 10% 10%
C2 5% 15% 15% 15% 15% 15% 15% 5%
C3 5% 15% 20% 25% 5% 10% 10% 10%
C4 5% 15% 30% 30% 5% 5% 10%
C5 5% 15% 35% 35% 10%


**SOM needs to define these terms more frequently. My doc is color-coded W/S and W/G and Baaaad errors), P/P, P/F, and PO are Yellow meh, FO, G1, G2 and G3 are green/good (outs)

I can't remember what W/S and W/G stand for, or understand from numerous rule books from early 2000s


3Roll %
3 0.46%
4 1.39%
5 2.78%
6 4.63%
7 6.94%
8 9.72%
9 11.57%
10 12.50%
11 12.50%
12 11.57%
13 9.72%
14 6.94%
15 4.63%
16 2.78%
17 1.39%
18 0.46%


E-Rating RarePlay E1 E2
0 2.78% 0.00% 0.00%
1 2.78% 1.39% 0.00%
2 2.78% 2.31% 0.00%
3 2.78% 3.70% 0.00%
4 2.78% 4.17% 0.46%
5 2.78% 5.55% 0.46%
6 2.78% 6.94% 0.46%
7 2.78% 7.87% 0.46%
8 2.78% 9.26% 0.46%
9 2.78% 10.19% 0.46%
10 2.78% 11.57% 0.46%
11 2.78% 12.96% 0.46%
12 2.78% 13.43% 0.93%
13 2.78% 14.81% 0.93%
14 2.78% 15.74% 0.93%
15 2.78% 17.13% 0.93%
16 2.78% 18.05% 0.93%

Catchers are the toughest defensively to value. I have ultimately settled on an inter related table of catcher arm plus T rating. Also catchers arms don’t necessarily do what you expect which is reduce sb success %. What you find is the better the arm the fewer the attempts, but sb % stays around 65-70%.

I can post later more details

The point above is that the catchers arm is a much more important aspect to defense value than the range and e rating

Great question and topic.It is likely the most nebulous of things to assign value for. Marc Pelletier , who I think did some of the finest and most transparent work on valuation*, if I recall, even admitted some rough order of magnitude assumptions in this area but seemed to believe catcher D was largely not as critical. I could be "misremembering", ala Clemens but that is my recollection.

Others have made the case that sometimes it can become more important dependent on the league conditions (which is where I fall). Whether it's the WP/PB game mechanics when men are on base, or the obvious T ratings against small ball teams, it is more difficult to assess using a universal calculus than many other things in the online game, IMO.

childsmwc is one of the stat nerds around here and has a quantitative grasp of the game mechanics, and his point below is well taken. He makes note that it is necessary to consider the second order effects.

Essentially, we need to try to account for the number of attempts the computer manager (HAL) will/won't make because of the arm. Because HAL is all about the probability of success and does not do nuance or discretion. It's a binary threshold of go/no-go and it is based on expectation of success. You can see this when he does weird things like makes the 3rd out in the 9th on a steal of 3rd base when you are a run down and have your best hitter at the plate. Something you would never do in real baseball--a cardinal sin. But HAL sees he is over his threshold for success even if by .01%, and he goes.

Very similar to the OF arm debate--but more complex because of the throwing errors.

This goes to what I think ggyuppie and others have lamented recently and at times with the game over the years--the beauty of the SOM engine is the face to face playing of the game. We don't have that in 365 and it takes away the human element of the competition and makes it into a planning exercise akin to setting up a domino trail.

*others have done great work too, but marc was always willing to share very detailed data

I must admit that I use more gut feel on catcher defense than any other position.
If I look around the league and see lots of speed, then a good arm is more important.
If I'm playing in a bomber park, I don't worry about a few throwing errors and passed balls.

As for the 1-5 ratings, the charts don't show much difference. Therefore, I'd rather have a
4(0)e4, T3(PB-3)
than a
1(0)e10, T5(PB-10)

As I gather/remember this and that on this topic, I"m reminded of its depth.

I was misrepresenting the value by just saying success rates as childsmwc helps illumate. Great SB managers speak of great results with Conservative Team Strategy----something I was never clever enough to try.

A catcher's arm's value is in affecting the denominator in SB attempts, not just the success rate. It is the arms thing in the OF FrankieT. I have simplistic NERP ratings for that that might get laughed out of the room (.25 NERP for each +/- away from 0. So W. Mays -5 is worth 1.25 NERP whereas T. Raines is -25. Oops, no positional consideration )

But its valuable in even some rough estimation. But maybe "league conditions" to compare against is needed. In my SB ratings I have the hitters' OBP put into consideration. Base-stealing with a .290 OBP shouldn't be as valuable as with a .390 OBP.

-------------------
Ex: A *4-6,12/- (18-13) basestealing is about 1.51 NERP at face value.
-Via OBP multiplier for Jackie Robinson 1949 and his .520 OBP, that steal rating should be worth about 1.49 NERP
-Via OBP multiplier for George Davis 1905 and his .354 OBP it should be worth less, say 1.09 NERP
--------------------

Something similar for catchers and ~league OBP and steal-aggression? Still an isolated (and kinda flawed) number is still achievable Reminds me of SP and being able to be successful vs 60mil intensity of opposing cards vs 100+ mil or even 80

Interesting to think about the total defensive value (so NERP) of Catchers being a pie-graph and how much goes to which of its ~4 ratings. childsmwc contends hypothetical SB dissuasion is like the most the biggest part of the pie! Awesome! Abstract, but those other parts gotta be less-so!

I must admit that I use more gut feel on catcher defense than any other position.
If I look around the league and see lots of speed, then a good arm is more important.
If I'm playing in a bomber park, I don't worry about a few throwing errors and passed balls.

As for the 1-5 ratings, the charts don't show much difference. Therefore, I'd rather have a
4(0)e4, T3(PB-3)
than a
1(0)e10, T5(PB-10)

and there boys that is what gets you a .560+ winning %--making discretionary judgements based on the league environment rather than seeking a universal statistic.
That isn't to diminish the value of this thread--it is a great question and topic as I said.

But sometimes in the absence of clarity it comes down to gut feel. I thought that was almost...poetic...similar to the idea that I don't like all the platoons either--but I try to beat them instead of joining them. But I certainly don't want to ban them just because I don't care for them.

Sometimes when I am deciding between two similar offensive catchers, I simply add up their ratings.

2(-1)e1 T3 PB 3 = 8 (2-1+1+3+3=8)

It's not an exact science certainly, but quickly weeds out the guys with bad E, PB or T ratings.

I mentioned it an other threads recently. I actually think Catcher's D is UNDER rated. A catcher with a T20 arm will absolutely kill you, he's gonna make 20-40 throwing errors a season which means at a minimum a runner is going from 2nd to 3rd and sometimes from 3rd to home.

And I've lost championships on WP's & PB's.

So with catchers, I never overlook the hidden details. The thing I worry about the least is the range. But I like E, PB & T ratings to all be below 5 if possible if I'm building a defense heavy team.

That's a pretty cool rule of thumb Rich