lowest era- by a player in a season with at least 148 ip between 1900 to 1987

Between the 1900 and 1987 seasons, Dutch Leonard had the best ERA- with 148.0+ innings pitched in a season, with an ERA- of 36 in 1914.

	NAME	ERA-	IP	SEASON	TM	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	FIP	FIP-	H/9	PRAA
1	Dutch Leonard D. Leonard	36	224.2	1914	BSA	36	19	5	.792	25	0.96	176	17	7	3	139	24	34	3	60	8	8		842	2	7.05	2.40	2.93	0.12	20.9	7.1	0.89	.229	1.36	1.95	70	5.57	20.4
2	Bob Gibson B. Gibson	38	304.2	1968	STL	34	22	9	.710	34	1.12	268	28	13	0	198	38	49	11	62	7	0	6	1,161	4	7.92	1.83	4.32	0.32	23.1	5.3	0.85	.230	1.45	1.77	63	5.85	34.8
3	Walter Johnson W. Johnson	39	346.0	1913	WSH	48	36	7	.837	36	1.14	243	29	11	2	232	44	56	9	38	9	10		1,271	2	6.32	0.99	6.39	0.23	19.1	3.0	0.78	.229	1.46	1.90	63	6.03	42.3
4	Mordecai Brown M. Brown	39	277.1	1906	CHC	36	26	6	.813	32	1.04	144	27	9	3	198	32	56	1	61	4	4		1,044	2	4.67	1.98	2.36	0.03	13.8	5.8	0.93	.236	1.82	2.08	75	6.43	21.1
5	Mark Eichhorn M. Eichhorn	41	157.0	1986	TOR	69	14	6	.700	0	1.72	166	0	0	10	105	30	32	8	45	7	38	14	612	2	9.52	2.58	3.69	0.46	27.1	7.4	0.96	.251	1.83	2.30	56	6.02	31.8
6	Walter Johnson W. Johnson	42	369.0	1912	WSH	50	33	12	.733	37	1.39	303	34	7	2	259	57	89	2	76	16	13		1,413	11	7.39	1.85	3.99	0.05	21.4	5.4	0.91	.253	2.17	2.03	63	6.32	49.6
7	Christy Mathewson C. Mathewson	42	338.2	1905	NYG	43	31	9	.775	37	1.28	206	32	8	3	252	48	85	4	64	1	6		1,294	6	5.47	1.70	3.22	0.11	15.9	4.9	0.93	.243	2.26	2.03	69	6.70	34.9
8	Grover Alexander G. Alexander	43	376.1	1915	PHN	49	31	10	.756	42	1.22	241	36	12	3	253	51	86	3	64	10	7		1,435	2	5.76	1.53	3.77	0.07	16.8	4.5	0.84	.224	2.06	1.82	63	6.05	44.1
9	Dwight Gooden D. Gooden	44	276.2	1985	NYM	35	24	4	.857	35	1.53	268	16	8	0	198	47	51	13	69	2	0	4	1,065	6	8.72	2.24	3.88	0.42	25.2	6.5	0.97	.259	1.66	2.12	59	6.44	45.6
10	Christy Mathewson C. Mathewson	44	275.1	1909	NYG	37	25	6	.806	33	1.14	149	26	8	2	192	35	57	2	36	0	4		998	4	4.87	1.18	4.14	0.07	14.9	3.6	0.83	.234	1.86	1.62	61	6.28	31.7
11	Cy Young C. Young	44	371.1	1901	BSA	43	33	10	.767	41	1.62	158	38	5	0	324	67	112	6	37	7	2		1,440	2	3.83	0.90	4.27	0.15	11.0	2.6	0.97	.258	2.71	2.64	72	7.85	42.6
12	Lefty Grove L. Grove	47	288.2	1931	PHA	41	31	4	.886	30	2.06	175	27	4	5	249	66	84	10	62	1	10		1,160	2	5.46	1.93	2.82	0.31	15.1	5.3	1.08	.262	2.62	3.01	70	7.76	40.8
13	Jack Pfiester J. Pfiester	47	195.0	1907	CHC	30	14	9	.609	22	1.15	90	13	3	0	143	25	61	1	48	5	5		745	2	4.15	2.22	1.88	0.05	12.1	6.4	0.98	.236	2.82	2.14	81	6.60	10.6
14	Walter Johnson W. Johnson	47	326.0	1918	WSH	39	23	13	.639	29	1.27	162	29	8	3	241	46	71	2	70	8	10		1,261	8	4.47	1.93	2.31	0.06	12.8	5.6	0.95	.235	1.96	2.04	74	6.65	25.9
15	Walter Johnson W. Johnson	48	290.1	1919	WSH	39	20	14	.588	29	1.49	147	27	7	2	235	48	73	0	51	7	10		1,131	4	4.56	1.58	2.88	0.00	13.0	4.5	0.99	.254	2.26	2.07	67	7.28	32.6
16	Carl Lundgren C. Lundgren	48	207.0	1907	CHC	28	18	7	.720	25	1.17	84	21	7	0	130	27	42	0	92	2	3		795	2	3.65	4.00	0.91	0.00	10.6	11.6	1.07	.211	1.83	2.73	104	5.65	-2.3
17	Ron Guidry R. Guidry	48	273.2	1978	NYY	35	25	3	.893	35	1.74	248	16	9	0	187	53	61	13	72	1	0	1	1,057	7	8.16	2.37	3.44	0.43	23.5	6.8	0.95	.241	2.01	2.18	58	6.15	48.5
18	Dean Chance D. Chance	48	278.1	1964	LAA	46	20	9	.690	35	1.65	207	15	11	4	194	51	56	7	86	2	7	9	1,093	9	6.69	2.78	2.41	0.23	18.9	7.9	1.01	.236	1.81	2.39	67	6.27	37.9
19	Ed Reulbach E. Reulbach	48	291.2	1905	CHC	34	18	14	.563	29	1.42	152	28	5	1	208	46	71	1	73	18	5		1,124	5	4.69	2.25	2.08	0.03	13.5	6.5	0.96	.235	2.19	2.46	85	6.42	14
20	Jack Taylor J. Taylor	49	333.2	1902	CHO	37	23	11	.676	34	1.29	88	34	8	1	273	48	86	2	45	12	3		1,278	10	2.37	1.21	1.96	0.05	6.9	3.5	0.95	.240	2.32	2.73	98	7.36	0.6
21	Addie Joss A. Joss	49	325.0	1908	CLE	42	24	11	.686	35	1.16	130	29	9	2	232	42	77	2	30	2	6		1,209	6	3.60	0.83	4.33	0.06	10.8	2.5	0.81	.220	2.13	1.68	76	6.42	19.3
22	Spud Chandler S. Chandler	50	253.0	1943	NYY	30	20	4	.833	30	1.64	134	20	5	0	197	46	62	5	54	4	0		989	3	4.77	1.92	2.48	0.18	13.5	5.5	0.99	.242	2.21	2.30	68	7.01	29.8
23	Billy Pierce B. Pierce	50	205.2	1955	CWS	33	15	10	.600	26	1.97	157	16	6	3	162	45	50	16	64	3	5	5	836	4	6.87	2.80	2.45	0.70	18.8	7.7	1.10	.245	2.19	2.83	72	7.09	24.5
24	Roger Craig R. Craig	50	152.2	1959	LAD	29	11	5	.688	17	2.06	76	7	4	0	122	35	49	13	45	1	3	3	612	2	4.48	2.65	1.69	0.77	12.4	7.4	1.09	.229	2.89	3.56	88	7.19	8.5
25	Dolf Luque D. Luque	50	322.0	1923	CIN	41	27	8	.771	37	1.93	151	28	6	2	279	69	90	2	88	5	4		1,301	4	4.22	2.46	1.72	0.06	11.6	6.8	1.14	.263	2.52	2.94	77	7.80	31