most innings pitched by a pitcher before the age of 25

Walter Johnson has pitched the most career innings by a pitcher younger than 25, with 1614.2 innings.

	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	Walter Johnson W. Johnson	1614.2	211	110	81	.576	182	0.08	1,156	158	31	6	1,256		487	12	360	66	28			74	6.44	2.01	3.21	0.07		5.7	1.00	.261	2.71	7.00
2	Bert Blyleven B. Blyleven	1611.1	216	95	85	.528	213	2.78	1,327	97	24	0	1,416	498	566	114	403	39	2	23	6,534	31	7.41	2.25	3.29	0.64	20.3	6.2	1.13	.280	3.16	7.91
3	Bob Feller B. Feller	1448.1	205	107	54	.665	175	3.18	1,233	117	16	10	1,149	512	569	58	815	26	24		6,187	46	7.66	5.06	1.51	0.36	19.9	13.2	1.36	.269	3.54	7.14
4	Larry Dierker L. Dierker	1409.0	205	83	68	.550	191	3.14	965	66	11	1	1,268	491	556	109	386	22	5	29	5,797	64	6.16	2.47	2.50	0.70	16.6	6.7	1.17	.269	3.55	8.10
5	Hal Newhouser H. Newhouser	1376.1	231	94	71	.570	173	2.86	895	94	19	10	1,165	438	537	38	673	6	43		5,852	29	5.85	4.40	1.33	0.25	15.3	11.5	1.34	.266	3.51	7.62
6	Catfish Hunter C. Hunter	1319.1	212	73	79	.480	190	3.53	882	50	13	1	1,170	518	574	151	424	24	4	29	5,471	22	6.02	2.89	2.08	1.03	16.1	7.7	1.21	.255	3.92	7.98
7	Dwight Gooden D. Gooden	1291.0	177	100	39	.719	175	2.64	1,168	52	19	1	1,053	379	423	65	379	18	1	17	5,215	26	8.14	2.64	3.08	0.45	22.4	7.3	1.11	.276	2.95	7.34
8	Fernando Valenzuela F. Valenzuela	1285.1	176	78	57	.578	166	2.89	1,032	64	23	1	1,069	413	485	68	455	9	4	35	5,261	41	7.23	3.19	2.27	0.48	19.6	8.6	1.19	.271	3.40	7.49
9	Pete Schneider P. Schneider	1273.1	207	59	86	.407	157	2.64	487	85	10	5	1,199		541	16	498	53	36			16	3.44	3.52	0.98	0.11		9.3	1.33	.274	3.82	8.47
10	Joe Wood J. Wood	1257.2	193	102	51	.667	141	0.59	933	111	25	6	992		453	9	369	51	45			40	6.68	2.64	2.53	0.06		7.3	1.08	.266	3.24	7.10
11	Waite Hoyt W. Hoyt	1243.1	195	82	57	.590	143	3.43	401	82	10	8	1,303	474	550	36	362	22	41		5,274	14	2.90	2.62	1.11	0.26	7.6	6.9	1.34	.285	3.98	9.43
12	Mike McCormick M. McCormick	1223.0	249	65	67	.492	171	3.83	724	47	12	8	1,198	521	584	135	439	11	35	43	5,206	39	5.33	3.23	1.65	0.99	13.9	8.4	1.34	.273	4.30	8.82
13	Earl Hamilton E. Hamilton	1221.0	195	57	77	.425	140	1.85	487	83	11	5	1,149		556	19	442	49	37		5,086	25	3.59	3.26	1.10	0.14	9.6	8.7	1.30	.276	4.10	8.47
14	Frank Tanana F. Tanana	1212.0	159	77	54	.588	154	2.72	1,010	79	21	0	1,034	366	407	105	322	39	3	22	4,927	30	7.50	2.39	3.14	0.78	20.5	6.5	1.12	.269	3.02	7.68
15	Don Drysdale D. Drysdale	1201.2	211	73	60	.549	163	3.28	927	52	15	4	1,084	438	486	115	383	67	30	36	5,033	29	6.94	2.87	2.42	0.86	18.4	7.6	1.22	.274	3.64	8.12
16	Mel Harder M. Harder	1198.0	236	75	68	.524	136	3.65	390	64	9	13	1,299	486	619	45	393	26	61		5,246	13	2.93	2.95	0.99	0.34	7.4	7.5	1.41	.286	4.65	9.76
17	Babe Ruth B. Ruth	1190.1	158	89	46	.659	143	2.19	495	105	17	4	934		376	9	433	29	11			27	3.74	3.27	1.14	0.07		9.0	1.15	.239	2.84	7.06
18	Milt Pappas M. Pappas	1186.0	198	82	60	.577	167	3.41	678	60	16	4	1,046	450	495	100	437	28	21	22	4,936	54	5.15	3.32	1.55	0.76	13.7	8.9	1.25	.256	3.76	7.94
19	Denny McLain D. McLain	1176.2	171	90	48	.652	164	3.11	917	70	17	1	933	406	449	151	355	15	2	9	4,737	17	7.01	2.72	2.58	1.15	19.4	7.5	1.09	.237	3.43	7.14
20	Felix Hernandez F. Hernandez	1170.2	174	72	54	.571	174	3.18	1,053	14	4	0	1,068	414	471	98	360	35	0	14	4,846	60	8.10	2.77	2.93	0.75	21.7	7.4	1.22	.294	3.62	8.21
21	Pete Donohue P. Donohue	1157.2	173	83	53	.610	146	3.29	344	88	10	8	1,236		518	26	222	26	22		4,858	7	2.67	1.73	1.55	0.20	7.1	4.6	1.26	.285	4.03	9.61
22	Gary Nolan G. Nolan	1156.2	169	76	47	.618	166	2.83	817	33	12	0	981	364	407	89	336	12	1	36	4,720	22	6.36	2.61	2.43	0.69	17.3	7.1	1.14	.257	3.17	7.63
23	Dennis Eckersley D. Eckersley	1148.1	171	77	50	.606	155	3.13	855	60	13	3	1,008	399	431	119	352	32	8	33	4,760	17	6.70	2.76	2.43	0.93	18.0	7.4	1.18	.261	3.38	7.90
24	Joe Coleman J. Coleman	1136.0	182	63	59	.516	161	3.43	797	52	10	1	1,034	433	487	92	394	38	6	23	4,765	50	6.31	3.12	2.02	0.73	16.7	8.3	1.26	.274	3.86	8.19
25	Van Mungo V. Mungo	1133.0	182	72	60	.545	141	3.50	623	77	12	7	1,071	440	503	45	450	13	30		4,845	24	4.95	3.57	1.38	0.36	12.9	9.3	1.34	.276	4.00	8.51