A while back, I ran a simulation of the various hit numbers. I then did the same thing, concentrating on the pitching grades. This time I’m going to look at fielding, including the arm ratings for catchers and outfielders. The latter prove to be pretty surprising.
First off let’s take a look at the most important stat when comparing the fielding ratings: run differential. I had previously established a baseline of 4.04 runs scored per 36 PA for the average 2012 replay. For all of the different fielding ratings, here are the variances away from that 4.04:
Usage 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
P 
.03 
.01 








C 




.07 
.05 
.00 
.04 
.04 

1B 

.10 
.02 
.01 
.06 





2B 




.14 
.08 
.04 
.02 
.04 

3B 

.08 
.06 
.03 
.07 
.06 




SS 





.15 
.10 
.01 
.06 
.09 
OF 
.05 
.03 
.01 







One of the things that sticks out is that the “average” rating (e.g.: 2B7, OF2) are slightly worse than average runwise. This is compensated somewhat (with the exception of 3B) by having the average rating of the position over the course of a replay be a little above average. For the outfielders, the sum of the OF divided by 3 is presented, as I had no way to isolate the simulations to just use a certain rating in one of the three fields:
Usage 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
Avg 
P 
.37 
.63 








1.63 
C 




.03 
.07 
.46 
.37 
.06 

7.35 
1B 

.15 
.35 
.28 
.22 





3.57 
2B 




.00 
.11 
.42 
.33 
.14 

7.50 
3B 

.00 
.43 
.37 
.19 
.00 




3.76 
SS 





.05 
.12 
.59 
.20 
.03 
8.05 
LF 
.28 
.53 
.19 







1.91 
CF 
.01 
.31 
.68 







2.67 
RF 
.21 
.48 
.31 







2.11 
There are only two positions where the replay average is below the theoretical average: third base (by a lot) and leftfield (by a little). In total, the team defense averages 38.54: 31.86 in the infield and 6.69 in the outfield. With the shift over the last 20 years of 3B producing the second most errors on a team (rather than 2B), upping the 2B ratings and lowering the 3B ratings is one way to do it.
Looking at the main purpose of the fielding rating (errors), there is little surprise in the correlation between the errors per 36 PA for a rating and the errors per 36 PA for an overall replay.
EDiff 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
Avg 
P 
.02 
.02 








.06 
C 




.11 
.08 
.01 
.06 
.07 

.10 
1B 

.06 
.01 
.02 
.04 





.06 
2B 




.12 
.09 
.01 
.02 
.04 

.08 
3B 

.02 
.02 
.01 
.05 
.07 




.10 
SS 





.08 
.05 
.00 
.08 
.10 
.15 
LF 
.03 
.01 
.03 







.05 
CF 
.06 
.02 
.01 







.03 
RF 
.04 
.00 
.02 







.04 
A little surprising is that the cliff between those positions where 2 away from the norm (e.g.: C5 and C7), the margin between 2 and 1 away is greater than +1 and +2 away. LF2 is a negative, and CF appears to be the least important position to have an OF3 in, while it is the most deadly to have an OF1. A LF3 can pay dividends, especially by neutralizing that pesky fielding 2 LF error with the bases empty.
A look at hits is not very surprising either, with not much difference between the bad fielders and the good ones:
HDiff 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
P 
.01 
.00 








C 




.03 
.03 
.02 
.02 
.02 

1B 

.06 
.00 
.01 
.02 





2B 




.05 
.01 
.02 
.01 
.01 

3B 

.03 
.03 
.03 
.02 
.02 




SS 





.04 
.03 
.01 
.00 
.02 
OF 
.03 
.01 
.01 







A bit of an anomaly at catcher, since the hits were up no matter what the rating. Makes me wonder if there is a little bit of an issue with the baseline I am using where the hits may have been a little low. I also have a feeling that the 3B6 simulation was a little bit of an outlier on the offense side, as both the run and hit differentials were worse than 3B5.
Let’s move on to the catcher’s throwing arm in respect to stopping (or enabling) the running game:
C 
4 
3 
2 
1 
0 
+1 
+2 
+3 
+4 
+5 
+6 
Avg 
Rdiff 
.05 
.04 
.02 
.03 
.00 
.01 
.00 
.00 
.01 
.01 
.00 

SB% 
.85 
.82 
.80 
.78 
.75 
.73 
.71 
.69 
.69 
.69 
.67 
.80 
SBA/36 
.66 
.65 
.65 
.65 
.65 
.63 
.57 
.50 
.45 
.37 
.33 
.63 
Usage 
.18 
.31 
.11 
.12 
.11 
.05 
.00 
.02 
.04 
.03 
.03 
1.21 
This was probably the largest surprise of this simulation. First off, that the average Throw rating was 1.21 (and a median of 3), contributing somewhat to a higher than expected 80% steal success rate. The reallife rate for 2012 was only 74%. I have a feeling that APBA is still basing the ratings off a strict percentage and not curving them. The rate when the MG first came out was in the mid60s, and a difference between what used to be an average of +1 in older sets going down to 1.21 roughly correlates to a 6% higher success rate.
Also noted that the success rate does go down as the throw rating gets better until about +3, at which it levels off. Taking over is a go/nogo call of sending the runner a lot less. I don’t have a Micromanager utility to check on Duke Robinson to be sure, but that would be my gut feeling. Duke also tended to steal more when then pitcher was higher rated, and laying off when lower rated.
And on the other end of the surprise, it turns out that the OF arm ratings actually have more influence than the defense ratings. Again, I could not split the run differences, but I could check on assists and the playing time of the individual ratings. To keep this from being too ridiculous, I only checked Arm ratings 20, 25, 30, 35 and 40. The usage figures below are based on 2022, 2327, 2832, 3337 and 3840.
OF 
20 
25 
30 
35 
40 
Rdiff 
.08 
.07 
.03 
.01 
.05 
LF A/36 
.07 
.05 
.06 
.07 
.08 
CF A/36 
.06 
.06 
.06 
.05 
.06 
RF A/36 
.07 
.07 
.09 
.10 
.12 
Usage LF 
.00 
.03 
.75 
.22 
.00 
Usage CF 
.00 
.01 
.38 
.59 
.01 
Usage RF 
.00 
.00 
.30 
.67 
.03 
An arm of 40 has more benefits than an OF3. And an arm of 20 has a higher penalty than an OF1. Interestingly, in the 2012 set the arm ratings only range from 2538. When it comes to assists (like errors, runs and hits), the centerfielder has the least influence of the three spots, with the rightfielder having the most. Just a little quirk of APBA to keep in mind when putting together your lineup.
When determining the whole value of a card by including the hit factors from the hitting articles, note that these are not on the same scale. The numbers in this article are based on every play on the field, whether or not the rating was used. The batting numbers only refer to the time that batter is hitting, so a factor must be either multiplied to the hitting numbers or divided from the fielding numbers depending on the expected batting position of the player (a batter batting 1st bats more often than a player batting 9th). If batting 1st3rd, multiply/divide (whichever you chose) by .12, 4th6th use .11 and 7th9th use .10.
Another way to look at it: the difference between a SS9 and a SS7 (a dilemma often seen when trying to determine who to play) is roughly equivalent to an extra 1 for a SS9:
 The difference between run differentials for a SS7 (.10) and a SS9 (.06) is .16.
 Just assuming the player bats in the middle of the lineup, you would divide .16 / .11 to get 1.45, which is roughly equivalent to the value of a 1 (1.50).
The other positions on the difference between the standard Fielding 3 and 1 are a little wacky compared to the defensive spectrum we’re used to, basically, don’t worry about 2B and OF so hard and the corners are pretty important:
 Third Base (difference between 3B5 and 3B3): .13 (equivalent to two extra 7s)
 First Baseman (difference between 1B4 and 1B2): .11 (equivalent to an extra 3)
 Second Baseman (difference between 2B8 and 2B6): .10 (equivalent to an extra 6)
 Catcher (difference between C8 and C6): .09 (equivalent to an extra 8 and a 9)
 Outfielder (by arm, difference between 35 and 25): .08 (equivalent to an extra 9 and a 10)
 Outfielder (difference between OF3 and OF1): .06 (equivalent to an extra 7) (RF is likely most important, a 1 should stay out of CF)
 Catcher (by arm, difference between +3 and 3): .04 (equivalent to an extra 9)
The C and OF differences are cumulative. For example a C8/Th+3 would be worth .13 better than a C6/Th3 (similar to the 3B5/3 split) and an OF3/35 would be .14 better than an OF1/25 (equivalent to an extra 6 and 9).
Next up will be the other things that can be a factor: batting handicaps, speed ratings and steal ratings .