Pat Caraway has given up the most earned runs in a month, with 52 earned runs in July 1931.

	NAME	ER	MONTH	G	W	L	W%	GS	ERA	SO	CG	SHO	SV	IP	H	R	HR	BB	HBP	GF	IBB	TBF	WP	K/9	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	H/9
1	Pat Caraway P. Caraway	52	July 1931	14	1	6	.143	6	11.41	10	0	0	1	41.0	73	59	7	26	1	5		223	2	2.20	5.71	0.38	1.54	4.5	11.7	2.41	.369	12.95	16.02
2	Nels Potter N. Potter	50	August 1938	9	1	6	.143	8	7.99	24	4	0	1	56.1	76	54	8	25	2	1		271	0	3.83	3.99	0.96	1.28	8.9	9.2	1.79	.321	8.63	12.14
3	Nels Potter N. Potter	45	August 1939	12	1	4	.200	5	7.28	17	1	0	0	55.2	86	54	7	25	3	5		275	3	2.75	4.04	0.68	1.13	6.2	9.1	1.99	.354	8.73	13.90
4	Dick Ellsworth D. Ellsworth	44	July 1966	8	1	7	.125	8	8.25	25	1	0	0	48.0	73	49	10	12	2	0	3	230	1	4.69	2.25	2.08	1.88	10.9	5.2	1.77	.348	9.19	13.69
5	Bob Feller B. Feller	43	August 1938	9	1	4	.200	7	7.59	43	2	0	1	51.0	56	45	4	53	2	2		259	3	7.59	9.35	0.81	0.71	16.6	20.5	2.14	.331	7.94	9.88
6	Bucky Walters B. Walters	42	July 1937	9	2	6	.250	8	6.52	18	3	1	0	58.0	75	44	6	27	2	0		272	4	2.79	4.19	0.67	0.93	6.6	9.9	1.76	.315	6.83	11.64
7	Earl Caldwell E. Caldwell	42	July 1936	8	1	5	.167	7	7.77	11	3	0	1	48.2	72	43	7	21	4	1		238	1	2.03	3.88	0.52	1.29	4.6	8.8	1.91	.333	7.95	13.32
8	Jack Knott J. Knott	42	July 1936	9	3	4	.429	6	7.36	22	3	0	0	51.1	83	47	3	21	2	3		255	3	3.86	3.68	1.05	0.53	8.6	8.2	2.03	.386	8.24	14.55
9	Fred Frankhouse F. Frankhouse	42	July 1935	7	1	4	.200	6	9.53	14	2	1	0	39.2	62	43	3	17	1	0		200	0	3.18	3.86	0.82	0.68	7.0	8.5	1.99	.358	9.76	14.07
10	Ray Benge R. Benge	42	July 1930	7	0	5	.000	7	8.66	10	1	0	0	43.2	72	54	6	14	1	0		218	1	2.06	2.89	0.71	1.24	4.6	6.4	1.97	.353	11.13	14.84
11	Bill Sherdel B. Sherdel	42	July 1929	7	1	5	.167	6	8.22	14	3	0	0	46.0	78	45	5	21	0	0		230	1	2.74	4.11	0.67	0.98	6.1	9.1	2.15	.384	8.80	15.26
12	Ray Benge R. Benge	42	June 1929	10	4	4	.500	7	6.59	30	4	2	0	57.1	78	43	6	17	1	1		265	0	4.71	2.67	1.76	0.94	11.3	6.4	1.66	.341	6.75	12.24
13	Nels Potter N. Potter	41	July 1939	9	0	4	.000	6	7.85	9	3	0	1	47.0	69	44	7	19	1	2		227	6	1.72	3.64	0.47	1.34	4.0	8.4	1.87	.325	8.43	13.21
14	Gordon Rhodes G. Rhodes	41	July 1936	8	1	6	.143	7	6.63	11	4	0	0	55.2	87	51	4	15	0	1		263	0	1.78	2.43	0.73	0.65	4.2	5.7	1.83	.356	8.25	14.07
15	Buck Ross B. Ross	41	July 1936	7	1	5	.167	7	8.79	8	2	1	0	42.0	66	44	3	17	0	0		206	1	1.71	3.64	0.47	0.64	3.9	8.3	1.98	.354	9.43	14.14
16	Bobo Newsom B. Newsom	41	August 1935	8	2	5	.286	8	6.75	13	5	0	0	54.2	70	45	2	29	2	0		252	2	2.14	4.77	0.45	0.33	5.2	11.5	1.81	.330	7.41	11.52
17	Earl Whitehill E. Whitehill	41	June 1935	7	1	4	.200	7	6.44	23	4	0	0	57.1	82	46	6	28	3	0		282	1	3.61	4.40	0.82	0.94	8.2	9.9	1.92	.342	7.22	12.87
18	Danny MacFayden D. MacFayden	41	July 1930	8	1	4	.200	8	6.33	12	4	0	0	58.1	87	43	2	23	0	0		275	0	1.85	3.55	0.52	0.31	4.4	8.4	1.89	.357	6.63	13.42
19	Jack Scott J. Scott	41	August 1927	10	0	5	.000	6	8.26	14	4	0	0	44.2	76	44	4	15	1	1		221	3	2.82	3.02	0.93	0.81	6.3	6.8	2.04	.385	8.87	15.31
20	Dick Barrett D. Barrett	40	June 1945	10	1	5	.167	7	10.00	13	0	0	1	36.0	61	45	2	14	1	2		186	2	3.25	3.50	0.93	0.50	7.0	7.5	2.08	.378	11.25	15.25
21	George Caster G. Caster	40	August 1938	9	4	4	.500	9	5.48	24	5	0	0	65.2	82	41	8	20	2	0		297	0	3.29	2.74	1.20	1.10	8.1	6.7	1.55	.305	5.62	11.24
22	Jim Walkup J. Walkup	40	July 1937	5	2	3	.400	5	9.00	8	2	0	0	40.0	64	42	5	17	0	0		197	3	1.80	3.83	0.47	1.13	4.1	8.6	2.03	.353	9.45	14.40
23	Vern Kennedy V. Kennedy	40	August 1936	8	4	3	.571	8	6.51	13	3	0	0	55.1	64	45	5	27	0	0		249	0	2.11	4.39	0.48	0.81	5.2	10.8	1.64	.289	7.32	10.41
24	Chief Hogsett C. Hogsett	40	July 1936	8	3	5	.375	7	6.92	26	2	0	0	52.0	78	44	6	21	3	1		258	0	4.50	3.63	1.24	1.04	10.1	8.1	1.90	.356	7.62	13.50
25	Bill Dietrich B. Dietrich	40	August 1935	7	1	5	.167	5	7.06	14	5	1	0	51.0	69	48	1	30	0	2		251	3	2.47	5.29	0.47	0.18	5.6	12.0	1.94	.330	8.47	12.18