John Coleman has given up the most runs in a season, with 510 runs in his rookie season in 1883.

Interpreted as:

most run in a season open era by a player

	NAME	R	ERA	SEASON	TM	G	W	L	W%	GS	SO	CG	SHO	SV	IP	H	ER	HR	BB	HBP	GF	TBF	WP	K/9	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	ERA-	FIP	FIP-	H/9	PRAA
1	John Coleman J. Coleman	510	4.87	1883	PHN	65	12	48	.200	61	159	59	3	0	538.1	772	291	17	48		4	2,546	9	2.66	0.80	3.31	0.28	6.2	1.9	1.52		8.53	158	3.34	109	12.91	-19.2
2	Will White W. White	404	1.99	1879	CIN	76	43	31	.581	75	232	75	4	0	680.0	676	150	10	68		1	2,906	49	3.07	0.90	3.41	0.13	8.0	2.3	1.09		5.35	84	2.55	107	8.95	-25.2
3	Bobby Mathews B. Mathews	395	2.86	1876	NYM	56	21	34	.382	56	37	55	2	0	516.0	693	164	8	24		0	2,327	3	0.65	0.42	1.54	0.14	1.6	1.0	1.39		6.89	128	2.43	109	12.09	-17.6
4	Phenomenal Smith P. Smith	369	3.79	1887	BAL	58	25	30	.455	55	206	54	1	0	491.1	526	207	7	176	14	3	2,204	12	3.77	3.22	1.17	0.13	9.3	8.0	1.43	.288	6.76	90	3.78	94	9.64	11.4
5	Pud Galvin P. Galvin	367	2.72	1883	BUF	76	46	29	.613	75	279	72	5	0	656.1	676	198	9	50		1	2,741	28	3.83	0.69	5.58	0.12	10.2	1.8	1.11		5.03	85	2.81	88	9.27	32
6	George Bradley G. Bradley	361	2.85	1879	TRO	54	13	40	.245	54	133	53	3	0	487.0	590	154	12	26		0	2,170	43	2.46	0.48	5.12	0.22	6.1	1.2	1.26		6.67	115	2.67	108	10.90	-12.6
7	Al Mays A. Mays	359	4.73	1887	NYM	52	17	34	.333	52	124	50	0	0	441.1	551	232	11	136	20	1	2,002	36	2.53	2.77	0.91	0.22	6.2	6.8	1.56	.316	7.32	113	4.10	102	11.24	-5.5
8	Kid Carsey K. Carsey	358	4.99	1891	WSH	54	14	37	.275	53	174	46	1	0	415.0	513	230	17	161	28	1	1,937	29	3.77	3.49	1.08	0.37	9.0	8.3	1.62	.319	7.76	133	3.59	99	11.13	2.3
9	Mark Baldwin M. Baldwin	358	3.61	1889	COL	63	27	34	.443	59	368	54	6	1	513.2	458	206	9	274	20	4	2,275	83	6.45	4.80	1.34	0.16	16.2	12.0	1.43	.280	6.27	100	3.52	98	8.02	-3
10	Toad Ramsey T. Ramsey	358	3.43	1887	LOU	65	37	27	.578	64	355	61	0	0	561.0	544	214	9	167	16	1	2,430	46	5.70	2.68	2.13	0.14	14.6	6.9	1.27	.284	5.74	78	3.20	76	8.73	64.2
11	Henry Gruber H. Gruber	352	4.27	1890	CLP	48	22	23	.489	44	110	39	1	0	383.1	464	182	15	204	15	4	1,839	36	2.58	4.79	0.54	0.35	6.0	11.1	1.74	.300	8.26	105	4.56	113	10.89	-27.7
12	Billy Crowell B. Crowell	350	4.88	1887	CLE	45	14	31	.311	45	72	45	1	0	389.1	541	211	9	138	20	0	1,812	23	1.66	3.19	0.52	0.21	4.0	7.6	1.74	.338	8.09	114	4.42	107	12.51	-13.2
13	Matt Kilroy M. Kilroy	350	3.37	1886	BAL	68	29	34	.460	68	513	66	5	0	583.0	476	218	10	182	19	0	2,469	61	7.92	2.81	2.82	0.15	20.8	7.4	1.13	.267	5.40	100	2.60	77	7.35	47
14	Larry McKeon L. McKeon	350	3.50	1884	IND	61	18	41	.305	60	308	59	2	0	512.0	488	199	20	94	18	1	2,185	36	5.41	1.65	3.28	0.35	14.1	4.3	1.14	.268	6.15	108	3.24	101	8.58	-1.7
15	Frank Mountain F. Mountain	345	3.60	1883	COL	59	26	33	.441	59	159	57	4	0	503.0	546	201	8	123		0	2,230	21	2.84	2.20	1.29	0.14	7.1	5.5	1.33		6.17	115	3.56	114	9.77	-33.3
16	Lee Richmond L. Richmond	343	3.74	1882	WOR	48	14	33	.298	46	123	44	0	0	411.0	525	171	11	88		2	1,876	26	2.69	1.93	1.40	0.24	6.6	4.7	1.49		7.51	121	3.16	105	11.50	0.8
17	Gus Weyhing G. Weyhing	342	4.27	1887	PHA	55	26	28	.481	55	193	53	2	0	466.1	465	221	12	167	37	0	2,042	49	3.72	3.22	1.16	0.23	9.5	8.2	1.36	.277	6.60	99	4.10	99	8.97	1.2
18	Mike Morrison M. Morrison	341	4.92	1887	CLE	40	12	25	.324	40	158	35	0	0	316.2	385	173	13	205	22	1	1,536	62	4.49	5.83	0.77	0.37	10.3	13.3	1.86	.327	9.69	115	4.96	120	10.94	-29.7
19	Hardie Henderson H. Henderson	339	4.39	1883	TOT	46	10	33	.233	43	147	39	0	0	367.1	409	179	4	89		3	1,638	32	3.60	2.18	1.65	0.10	9.0	5.4	1.36		8.31	134	3.32	101	10.02	-1.4
20	Jersey Bakley J. Bakley	338	4.29	1884	TOT	46	16	30	.348	45	226	43	1	0	394.2	443	188	0	81		1	1,752	56	5.15	1.85	2.79	0.00	12.9	4.6	1.33		7.71	144	2.74	106	10.10	-9.3
21	Henry Porter H. Porter	336	4.16	1888	KCC	55	18	37	.327	54	145	53	4	0	474.0	527	219	16	120	23	1	2,084	24	2.75	2.28	1.21	0.30	7.0	5.8	1.36	.287	6.38	127	3.32	106	10.01	-1.6
22	Park Swartzel P. Swartzel	334	4.32	1889	KCC	48	19	27	.413	47	147	45	0	1	410.1	481	197	21	117	23	1	1,837	37	3.22	2.57	1.26	0.46	8.0	6.4	1.46	.301	7.33	106	3.98	98	10.55	9.2
23	George Cobb G. Cobb	333	4.86	1892	BAL	53	10	37	.213	47	159	42	0	0	394.1	495	213	21	140	19	6	1,836	15	3.63	3.20	1.14	0.48	8.7	7.6	1.61	.317	7.60	145	3.53	105	11.30	-6.1
24	Fleury Sullivan F. Sullivan	328	4.20	1884	PIT	51	16	35	.314	51	189	51	2	0	441.0	496	206	15	96	20	0	1,967	25	3.86	1.96	1.97	0.31	9.6	4.9	1.34	.292	6.69	131	3.65	115	10.12	-24.7
25	Bob Barr B. Barr	327	3.94	1884	TOT	48	12	34	.261	48	207	47	2	0	413.0	471	181	11	50	18	0	1,853	39	4.51	1.09	4.14	0.24	11.2	2.7	1.26	.294	7.13	125	3.11	100	10.26	-3.1