lowest era by a rookie pitcher since 1920

Since 1920, Stan Bahnsen has the lowest ERA by a rookie, with an ERA of 2.05 in 1968.

Interpreted as:

lowest era with a minimum of 1 IP per team game by a rookie pitcher since 1920

	NAME	ERA	SEASON	TM	G	W	L	W%	GS	SO	CG	SHO	SV	IP	H	ER	R	HR	BB	HBP	GF	IBB	TBF	WP	K/9	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	ERA-	FIP	FIP-	H/9	PRAA
1	Stan Bahnsen S. Bahnsen	2.05	1968	NYY	37	17	12	.586	34	162	10	1	0	267.1	216	61	72	14	68	2	3	6	1,070	4	5.45	2.29	2.38	0.47	15.1	6.4	1.06	.245	2.42	73	2.64	88	7.27	10.1
2	Jerry Koosman J. Koosman	2.08	1968	NYM	35	19	12	.613	34	178	17	7	0	263.2	221	61	72	16	69	8	0	7	1,058	8	6.08	2.36	2.58	0.55	16.8	6.5	1.10	.260	2.46	70	2.70	96	7.54	3.7
3	Johnny Beazley J. Beazley	2.13	1942	SLN	43	21	6	.778	23	91	13	3	3	215.1	181	51	67	4	73	3	15		890	7	3.80	3.05	1.25	0.17	10.2	8.2	1.18	.246	2.80	63	2.87	82	7.57	15.3
4	Jose Fernandez J. Fernandez	2.19	2013	MIA	28	12	6	.667	28	187	0	0	0	172.2	111	42	47	10	58	5	0	5	681	3	9.75	3.02	3.22	0.52	27.5	8.5	0.98	.240	2.45	60	2.72	75	5.79	18.1
5	Elmer Riddle E. Riddle	2.24	1941	CIN	33	19	4	.826	22	80	15	4	1	216.2	180	54	68	8	59	5	4		884	2	3.32	2.45	1.36	0.33	9.0	6.7	1.10	.235	2.82	62	3.29	89	7.48	9.6
6	Wilcy Moore W. Moore	2.28	1927	NYY	50	19	7	.731	12	75	6	1	13	213.0	185	54	68	3	59	1	30		870	4	3.17	2.49	1.27	0.13	8.6	6.8	1.15	.249	2.87	57	3.35	85	7.82	13.7
7	Mickey Haefner M. Haefner	2.29	1943	WSH	36	11	5	.688	13	65	8	1	6	165.1	126	42	56	4	60	4	17		679	3	3.54	3.27	1.08	0.22	9.6	8.8	1.13	.223	3.05	72	3.11	95	6.86	2.7
8	Jon Matlack J. Matlack	2.32	1972	NYM	34	15	10	.600	32	169	8	4	0	244.0	215	63	79	14	71	2	1	14	1,003	7	6.23	2.62	2.38	0.52	16.8	7.1	1.17	.269	2.91	69	2.65	81	7.93	16.5
9	Gary Peters G. Peters	2.33	1963	CWS	41	19	8	.704	30	189	13	4	1	243.0	192	63	69	9	68	8	4	2	978	5	7.00	2.52	2.78	0.33	19.3	7.0	1.07	.260	2.56	67	2.34	67	7.11	32.1
10	Mark Fidrych M. Fidrych	2.34	1976	DET	31	19	9	.679	29	97	24	4	0	250.1	217	65	76	12	53	3	2	3	996	6	3.49	1.91	1.83	0.43	9.7	5.3	1.08	.247	2.73	63	3.15	86	7.80	13.7
11	Mike Garcia M. Garcia	2.36	1949	CLE	41	14	5	.737	20	94	8	5	2	175.2	154	46	51	6	60	2	10		718	1	4.82	3.07	1.57	0.31	13.1	8.4	1.22	.266	2.61	59	2.94	73	7.89	21.3
12	Jim Turner J. Turner	2.38	1937	BSN	33	20	11	.645	30	69	24	5	1	256.2	228	68	80	13	52	0	3		1,031	0	2.42	1.82	1.33	0.46	6.7	5.0	1.09	.240	2.81	66	3.77	101	7.99	-3.1
13	Ernie White E. White	2.40	1941	SLN	32	17	7	.708	25	117	12	3	2	210.0	169	56	72	12	70	6	6		866	3	5.01	3.00	1.67	0.51	13.5	8.1	1.14	.238	3.09	64	3.38	88	7.24	11
14	Hoyt Wilhelm H. Wilhelm	2.43	1952	NYG	71	15	3	.833	0	108	0	0	11	159.1	127	43	60	12	57	5	32		646	3	6.10	3.22	1.89	0.68	16.7	8.8	1.15	.248	3.39	65	3.18	86	7.17	9.3
15	Gene Bearden G. Bearden	2.43	1948	CLE	37	20	7	.741	29	80	15	6	1	229.2	187	62	72	9	106	3	4		935	5	3.13	4.15	0.75	0.35	8.6	11.3	1.28	.242	2.82	60	3.90	99	7.33	0.4
16	Ewell Blackwell E. Blackwell	2.45	1946	CIN	33	9	13	.409	25	100	10	5	0	194.1	160	53	62	1	79	4	5		803	4	4.63	3.66	1.27	0.05	12.5	9.8	1.23	.257	2.87	74	2.70	80	7.41	14.5
17	Fernando Valenzuela F. Valenzuela	2.48	1981	LAD	25	13	7	.650	25	180	11	8	0	192.1	140	53	55	11	61	1	0	4	758	4	8.42	2.85	2.95	0.51	23.7	8.0	1.05	.255	2.57	73	2.44	72	6.55	20.4
18	Milo Candini M. Candini	2.49	1943	WSH	28	11	7	.611	21	67	8	3	1	166.0	144	46	55	3	65	1	5		681	5	3.63	3.52	1.03	0.16	9.8	9.5	1.26	.259	2.98	78	3.04	93	7.81	4
19	Hank Borowy H. Borowy	2.52	1942	NYY	25	15	4	.789	21	85	13	4	1	178.1	157	50	56	6	66	0	2		747	3	4.29	3.33	1.29	0.30	11.4	8.8	1.25	.256	2.83	70	3.01	87	7.92	8.7
20	Ken Forsch K. Forsch	2.53	1971	HOU	33	8	8	.500	23	131	7	2	0	188.1	162	53	60	8	53	4	4	5	771	8	6.26	2.53	2.47	0.38	17.0	6.9	1.14	.268	2.87	75	2.52	76	7.74	16.7
21	Butch Wensloff B. Wensloff	2.54	1943	NYY	29	13	11	.542	27	105	18	1	1	223.1	179	63	80	7	70	1	1		905	2	4.23	2.82	1.50	0.28	11.6	7.7	1.11	.238	3.22	77	2.84	84	7.21	13.1
22	Hideo Nomo H. Nomo	2.54	1995	LAD	28	13	6	.684	28	236	4	3	0	191.1	124	54	63	14	78	5	0	2	780	19	11.10	3.67	3.03	0.66	30.3	10.0	1.06	.246	2.96	65	2.88	71	5.83	26.1
23	Al Downing A. Downing	2.56	1963	NYY	24	13	5	.722	22	171	10	4	0	175.2	114	50	52	7	80	0	2	1	707	5	8.76	4.10	2.14	0.36	24.2	11.3	1.10	.238	2.66	73	2.42	68	5.84	22.3
24	Nate Andrews N. Andrews	2.57	1943	BSN	36	14	20	.412	34	80	23	3	0	283.2	253	81	100	11	75	6	2		1,167	4	2.54	2.38	1.07	0.35	6.9	6.4	1.16	.243	3.17	75	3.21	96	8.03	4.4
25	Gary Nolan G. Nolan	2.58	1967	CIN	33	14	8	.636	32	206	8	5	0	226.2	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	71	2.64	76	7.66	20.6