lowest era by a starting pitcher since 1920 to 1940 with at least 20 games started in a single season

Between the 1920 and 1940 seasons, Carl Hubbell had the best ERA by a starting pitcher with 20+ starts in a season, with an ERA of 1.77 in 1933.

	NAME	ERA	GS	SEASON	TM	G	W	L	W%	SO	CG	SHO	SV	IP	H	ER	R	HR	BB	HBP	GF	TBF	WP	K/9	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	H/9
1	Carl Hubbell C. Hubbell	1.77	33	1933	NYG	33	20	11	.645	139	22	10	0	274.0	231	54	66	6	42	3	0	1,074	3	4.57	1.38	3.31	0.20	12.9	3.9	1.00	.255	2.17	7.59
2	Lefty Grove L. Grove	1.94	30	1931	PHA	30	27	3	.900	144	27	4	0	260.1	223	56	73	9	57	1	0	1,044	2	4.98	1.97	2.53	0.31	13.8	5.5	1.08	.257	2.52	7.71
3	Grover Alexander G. Alexander	1.94	40	1920	CHC	40	26	14	.650	167	33	7	0	357.1	334	77	96	8	67	1	0	1,426	2	4.21	1.69	2.49	0.20	11.7	4.7	1.12	.276	2.42	8.41
4	Lon Warneke L. Warneke	1.97	34	1933	CHC	34	18	13	.581	131	26	4	0	282.2	254	62	80	8	75	3	0	1,153	6	4.17	2.39	1.75	0.25	11.4	6.5	1.16	.263	2.55	8.09
5	Dolf Luque D. Luque	1.98	37	1923	CIN	37	26	8	.765	149	28	6	0	309.1	267	68	89	2	87	5	0	1,253	4	4.34	2.53	1.71	0.06	11.9	6.9	1.14	.262	2.59	7.77
6	Hal Schumacher H. Schumacher	2.06	33	1933	NYG	33	19	11	.633	96	21	7	0	257.2	197	59	68	8	82	1	0	1,021	3	3.35	2.86	1.17	0.28	9.4	8.0	1.08	.227	2.38	6.88
7	Dazzy Vance D. Vance	2.06	32	1928	BKN	32	21	9	.700	194	24	4	0	274.2	220	63	78	10	68	6	0	1,097	1	6.36	2.23	2.85	0.33	17.7	6.2	1.05	.256	2.56	7.21
8	Bucky Walters B. Walters	2.13	36	1939	CIN	36	27	8	.771	131	31	2	0	312.0	239	74	91	15	102	6	0	1,246	7	3.78	2.94	1.28	0.43	10.5	8.2	1.09	.226	2.63	6.89
9	Bill Walker B. Walker	2.14	28	1931	NYG	28	16	9	.640	116	19	6	0	218.1	197	52	69	5	61	3	0	909	2	4.78	2.51	1.90	0.21	12.8	6.7	1.18	.265	2.84	8.12
10	Urban Shocker U. Shocker	2.18	38	1922	SLA	38	21	16	.568	143	29	2	0	330.0	344		133	22	56	4	0	1,369	2	3.90	1.53	2.55	0.60	10.4	4.1	1.21	.281	3.63	9.38
11	Dazzy Vance D. Vance	2.19	34	1924	BKN	34	27	6	.818	256	30	3	0	304.0	237	74	88	11	76	7	0	1,207	4	7.58	2.25	3.37	0.33	21.2	6.3	1.03	.264	2.61	7.02
12	Babe Adams B. Adams	2.21	33	1920	PIT	33	17	13	.567	81	18	8	0	256.0	238	63	83	6	17	1	0	1,014	5	2.85	0.60	4.76	0.21	8.0	1.7	1.00	.255	2.92	8.37
13	Burleigh Grimes B. Grimes	2.24	33	1920	BKN	33	21	10	.677	121	25	5	0	285.2	251	71	94	5	58	4	0	1,163	8	3.81	1.83	2.09	0.16	10.4	5.0	1.08	.252	2.96	7.91
14	Lefty Gomez L. Gomez	2.26	33	1934	NYY	33	25	3	.893	150	25	6	0	275.1	216	69	82	12	91	0	0	1,112	3	4.90	2.97	1.65	0.39	13.5	8.2	1.12	.237	2.68	7.06
15	Carl Hubbell C. Hubbell	2.27	34	1936	NYG	34	24	6	.800	116	25	3	0	290.0	250	73	76	6	54	5	0	1,145	2	3.60	1.68	2.15	0.19	10.1	4.7	1.05	.253	2.36	7.76
16	Jim Turner J. Turner	2.31	30	1937	BSN	30	20	10	.667	67	24	5	0	249.1	220	64	76	12	51	0	0	1,001	0	2.42	1.84	1.31	0.43	6.7	5.1	1.09	.239	2.74	7.94
17	Lefty Gomez L. Gomez	2.33	34	1937	NYY	34	21	11	.656	194	25	6	0	278.1	233	72	88	10	93	1	0	1,146	2	6.27	3.01	2.09	0.32	16.9	8.1	1.17	.263	2.85	7.53
18	Lon Warneke L. Warneke	2.38	32	1932	CHC	32	21	5	.808	108	25	4	0	272.1	244	72	83	12	63	2	0	1,101	4	3.57	2.08	1.71	0.40	9.8	5.7	1.13	.253	2.74	8.06
19	Carl Hubbell C. Hubbell	2.38	35	1934	NYG	35	20	12	.625	104	25	5	0	283.1	256	75	91	16	32	2	0	1,131	1	3.30	1.02	3.25	0.51	9.2	2.8	1.02	.246	2.89	8.13
20	Ray Kremer R. Kremer	2.41	28	1927	PIT	28	17	6	.739	56	18	3	0	216.1	197	58	66	9	44	0	0	871	2	2.33	1.83	1.27	0.37	6.4	5.1	1.11	.247	2.75	8.20
21	Monty Stratton M. Stratton	2.42	21	1937	CWS	21	15	5	.750	68	14	5	0	163.2	141	44	55	6	37	2	0	647	0	3.74	2.03	1.84	0.33	10.5	5.7	1.09	.253	3.02	7.75
22	Grover Alexander G. Alexander	2.45	30	1927	SLN	30	19	9	.679	45	22	2	0	253.2	245	69	85	10	33	1	0	1,019	0	1.60	1.17	1.36	0.35	4.4	3.2	1.10	.253	3.02	8.69
23	Dutch Ruether D. Ruether	2.45	33	1920	CIN	33	16	11	.593	98	23	5	0	261.0	232	71	85	1	95	9	0	1,069	6	3.38	3.28	1.03	0.03	9.2	8.9	1.25	.267	2.93	8.00
24	Wilbur Cooper W. Cooper	2.45	37	1920	PIT	37	22	14	.611	108	28	3	0	305.0	285	83	106	4	45	10	0	1,221	1	3.19	1.33	2.40	0.12	8.8	3.7	1.08	.267	3.13	8.41
25	Red Faber R. Faber	2.46	39	1921	CWS	39	24	14	.632	121	32	4	0	322.1	284	88	104	10	83	6	0	1,314	3	3.38	2.32	1.46	0.28	9.2	6.3	1.14	.250	2.90	7.93