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, year-by-year), 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% |
|