Bob Feller has pitched the most career innings by a pitcher younger than 20, with 488.1 innings.

Interpreted as:

most innings pitched before turning 20 years old by a player

	NAME	IP	G	W	L	W%	GS	ERA	SO	CG	SHO	SV	H	ER	R	HR	BB	HBP	GF	IBB	TBF	WP	K/9	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	H/9
1	Bob Feller B. Feller	488.1	79	31	21	.596	63	3.78	466	34	2	3	393	205	233	18	361	13	12		2,175	18	8.59	6.65	1.29	0.33	21.4	16.6	1.54	.285	4.29	7.24
2	Pete Schneider P. Schneider	333.1	61	15	23	.395	38	2.59	137	20	3	3	309		144	2	133	14	18			1	3.70	3.59	1.03	0.05		9.4	1.33	.273	3.89	8.34
3	Larry Dierker L. Dierker	328.1	56	16	16	.500	46	3.29	214	8	2	0	304	120	141	33	84	4	4	6	1,370	13	5.87	2.30	2.55	0.90	15.6	6.1	1.18	.262	3.86	8.33
4	Mike McCormick M. McCormick	259.2	69	14	10	.583	35	4.58	138	9	2	1	278	132	147	27	101	6	13	8	1,130	10	4.78	3.50	1.37	0.94	12.2	8.9	1.46	.293	5.09	9.64
5	Gary Nolan G. Nolan	226.2	33	14	8	.636	32	2.58	206	8	5	0	193	65	73	18	62	5	1	7	932	3	8.18	2.46	3.32	0.71	22.1	6.7	1.13	.273	2.90	7.66
6	Dwight Gooden D. Gooden	218.0	31	17	9	.654	31	2.60	276	7	3	0	161	63	72	7	73	2	0	2	879	3	11.39	3.01	3.78	0.29	31.4	8.3	1.07	.296	2.97	6.65
7	Wally Bunker W. Bunker	218.0	30	19	6	.760	30	2.89	97	12	1	0	171	70	78	18	65	3	0	5	875	3	4.00	2.68	1.49	0.74	11.1	7.4	1.08	.221	3.22	7.06
8	Curt Simmons C. Simmons	214.2	38	9	15	.375	29	4.74	119	9	0	0	213	113	131	9	131	2	5		973	6	4.99	5.49	0.91	0.38	12.2	13.5	1.60	.287	5.49	8.93
9	David Clyde D. Clyde	210.1	46	7	17	.292	39	4.66	126	4	0	0	235	109	127	22	101	8	4	1	938	13	5.39	4.32	1.25	0.94	13.4	10.8	1.60	.313	5.43	10.06
10	Frank Shellenback F. Shellenback	183.2	28	9	12	.429	21	2.65	46	10	2	2	180		77	1	78	6	6		783	0	2.25	3.82	0.59	0.05	5.9	10.0	1.40	.275	3.77	8.82
11	Joe Wood J. Wood	183.1	30	12	8	.600	21		107	14	5	0	135		63	1	57	9	6		727	5	5.25	2.80	1.88	0.05	14.7	7.8	1.05	.242	3.09	6.63
12	Hal Newhouser H. Newhouser	176.1	34	12	11	.522	26	4.64	116	10	0	0	184	91	104	13	112	2	3		808	5	5.92	5.72	1.04	0.66	14.4	13.9	1.68	.303	5.31	9.39
13	Milt Pappas M. Pappas	166.1	41	13	10	.565	24	4.06	94	4	0	0	162	75	82	8	68	2	9	2	708	10	5.09	3.68	1.38	0.43	13.3	9.6	1.38	.287	4.44	8.77
14	Bert Blyleven B. Blyleven	164.0	27	10	9	.526	25	3.18	135	5	1	0	143	58	66	17	47	2	1	6	675	2	7.41	2.58	2.87	0.93	20.0	7.0	1.16	.266	3.62	7.85
15	Ray Sadecki R. Sadecki	157.1	26	9	9	.500	26	3.78	95	7	1	0	148	66	76	15	86	1	0	1	689	8	5.43	4.92	1.10	0.86	13.8	12.5	1.49	.270	4.35	8.47
16	Ray Keating R. Keating	155.0	27	4	13	.235	22	2.38	88	10	2	0	153		89	2	59	2	3		667	4	5.11	3.43	1.49	0.12	13.2	8.8	1.37	.293	5.17	8.88
17	Ralph Branca R. Branca	154.1	37	5	8	.385	16	4.20	86	7	0	2	119	72	80	6	111	5	11		690	10	5.02	6.47	0.77	0.35	12.5	16.1	1.49	.234	4.67	6.94
18	Rube Bressler R. Bressler	147.2	29	10	4	.714	10	1.77	96	8	1	2	112	29	37	1	56	4	15		582	3	5.85	3.41	1.71	0.06	16.5	9.6	1.14	.261	2.26	6.83
19	Jim Waugh J. Waugh	142.2	46	5	11	.313	18	6.43	41	2	0	0	169	102	113	25	88	2	9		674	3	2.59	5.55	0.47	1.58	6.1	13.1	1.80	.278	7.13	10.66
20	Jim Brillheart J. Brillheart	137.2	43	4	7	.364	10	4.05	56	3	0	1	148	62	73	4	85	9	22		628	4	3.66	5.56	0.66	0.26	8.9	13.5	1.69	.304	4.77	9.68
21	Jack Bentley J. Bentley	135.0	33	6	7	.462	12	2.20	58	3	2	5	115	33	49	3	55	4	15		541	4	3.87	3.67	1.05	0.20	10.7	10.2	1.26	.266	3.27	7.67
22	Catfish Hunter C. Hunter	133.0	32	8	8	.500	20	4.26	83	3	2	0	124	63	68	21	46	2	2	5	567	2	5.62	3.11	1.80	1.42	14.6	8.1	1.28	.248	4.60	8.39
23	Bob Miller B. Miller	111.2	49	2	3	.400	2	3.71	37	0	0	1	112	46	54	5	52	1	32		486	4	2.98	4.19	0.71	0.40	7.6	10.7	1.47	.274	4.35	9.03
24	Walt Masterson W. Masterson	110.2	35	5	5	.500	11	5.04	43	3	0	0	111	62	77	3	83	3	17		519	4	3.50	6.75	0.52	0.24	8.3	16.0	1.75	.279	6.26	9.03
25	Johnny Antonelli J. Antonelli	99.0	26	3	7	.300	10	3.55	48	3	1	1	101	39	50	6	45	2	10		430	3	4.36	4.09	1.07	0.55	11.2	10.5	1.47	.289	4.55	9.18