DIPS Bands
How many pitchers are better or worse than their teammates in preventing hits
By Tangotiger
The following are results of a small study I ran. It is provided with no analysis.
Note that the numbers are subject to selective sampling. Pitchers receive playing time based on their perceived or determined talent level. This determination is made, partly/mostly on the sample performance of the pitcher. Any analysis should bear this in mind.
Here is an example of how the calculations were made.
 Greg Maddux (through 2000 I think) had an estimated 10,414 BIP. His $H is .270, while his teammates' $H (weighted by the BIP of Maddux, yearbyyear), is .278.
 I took his teammates' .278 as the "true mean", and calculated that 1 SD = sqrt(.278 x .712 / 10414) = .0044.
 Maddux is .0080 better than his teammates. He is .0080/.0044 (1.8) SDs from the mean.
 I did this for all pitchers, using their BIP as "n".
The following table is based on all pitchers born since 1900. The following is an explanation of each column:
 n : number of pitchers in the subgroup
 BIP : minimum number of BIP in the subgroup (with no overlapping with the other groups)
 LT 1 : like the Maddux above, pitchers who were more than 1 SD away from their teammates, but on the "good" side
 within 1 : all pitchers within 1 SD of their teammates
 GT +1 : pitchers who were more than 1 SD away from their teammates, but on the "bad" side
 % : next three columns are the percentages of the above three columns
n 
BIP 
LT 1 
within 1 
GT 1 
% better 1 SD 
% within 1 SD 
% worse 1 SD 
20 
12800 
9 
8 
3 
45% 
40% 
15% 
244 
6400 
75 
134 
35 
31% 
55% 
14% 
449 
3200 
119 
267 
63 
27% 
59% 
14% 
639 
1600 
121 
410 
108 
19% 
64% 
17% 
555 
800 
99 
355 
101 
18% 
64% 
18% 
540 
400 
67 
368 
105 
12% 
68% 
19% 
506 
200 
40 
359 
107 
8% 
71% 
21% 
1898 
1 
172 
1230 
496 
9% 
65% 
26% 
