youth gone wild

Kaz Ishii, who turns 32 next month, is nearly 3.5 years older than the average Biggio plunking pitcher - 28.5. Biggio has been hit most often by 26 year old pitchers. However, rather than 26 year olds being more likely to hit batters than other aged pitcher, this is probably most likely due to the over abundance of 26 year old pitchers in the league. During Biggio's career (through '04) 26 year olds have thrown 65,548.67 innings, trailing only 27 year olds.

Biggio's HBPs by Pitcher's age

Age	Biggio plunks
26	31
28	27
25	26
29	24
30	23
24	21
32	19
27	17
31	17
23	14
22	14
33	12
34	6
21	4
36	2
39	2
37	2
41	2
40	2
38	2
20	1
35	1

Historically, the 26 year olds have ranked only 7th in hit batters per inning pitched at 0.0253, but their is very little variance between the ages. The leaders, age 22 at 0.0274, only hit batters about 29% more often than the most infrequent plunking ages (excluding ages at which less than 20 players pitched).

Plunks per inning - all time

Age	Plunks	Innings	Pitchers	Plunks per Inning
22	3091	112615.333333	1508	0.027447
24	6275	240260.666666	2829	0.026115
25	7292	282210.666666	3324	0.025836
23	4562	176658.666666	2188	0.025821
28	7614	299400.666666	3113	0.025428
29	6871	270813.333333	2749	0.025371
26	7896	312569.666666	3458	0.02526
43	99	4025	56	0.024594
41	278	11310	131	0.024579
27	7843	320845	3402	0.024444
21	1539	64241.333333	913	0.023955
31	4823	201612.333333	2045	0.023922
39	533	22606.666666	249	0.023577
30	5560	235942.333333	2354	0.023565
32	3947	169280	1712	0.023316
42	166	7138.333333	83	0.023253
33	3236	139863.333333	1414	0.023136
35	1977	85737.666666	898	0.023058
38	766	33378.333333	384	0.022947
19	244	10774.666666	182	0.022644
37	1038	45976.666666	498	0.022575
36	1448	64464	688	0.022461
34	2501	111944.333333	1135	0.022341
20	590	26493.666666	474	0.022269
40	383	17252	179	0.0222
44	52	2343.333333	29	0.022188
18	84	4034	79	0.020823

During Biggio's career it has been the older pitchers who have been hitting batters most frequently. The 45 and 46 year old groups are heavily skewed by Nolan Ryan and Charlie Hough, but the 18 pitchers who pitched at age 42 hit 70 batters in 1571.33 innings - 45% more often per inning than the 30 year olds.

Plunks per inning 1988-2004

Age	Plunks	Innings	Pitchers	Plunks per Inning
46	17	277.33	4	0.061296
45	26	565	4	0.046017
42	70	1571.33	18	0.044547
40	155	3868.67	44	0.040065
21	139	3549.33	78	0.039162
43	38	976.67	12	0.038907
39	205	5487.33	65	0.037356
38	338	9217.67	99	0.036666
41	114	3141	34	0.036294
20	17	471.67	18	0.036042
37	449	12471.33	146	0.036
24	1591	45506	652	0.034962
26	2278	65548.67	952	0.034752
28	2177	62709.33	840	0.034713
27	2311	67122.67	961	0.034428
23	950	28073.33	425	0.033837
25	1892	55925	888	0.033831
22	457	13696.67	228	0.033363
29	1946	58910.33	755	0.033033
33	1089	33550	391	0.032457
31	1509	46510.67	557	0.032442
34	887	27897.67	319	0.031794
44	15	472.33	7	0.031755
36	526	16761	238	0.03138
35	664	21502	298	0.030879
32	1237	40308	547	0.030687
30	1585	51760.67	697	0.030621

Craig Biggio has been hit 55 times by pitchers older than him, and 214 times by younger pitchers.

Note: for pitchers who hit Craig Biggio with a pitch I used actual age of pitchers on the date they hit Biggio, but for historical plunk data I used the age the season during the year in which they turned a given age (season minus birthyear), so players who turned 28 in December were consider to be 28 for the season. Because it was easier.