Since 1903, the New York Yankees have their worst on-base percentage in a month in October 2017, with an on-base percentage of .188.

	TEAM	OBP	MONTH	G	W%	W	L	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	AVG	SLG	OPS
1	Yankees	.188	October 2017	1	.000	0	1	31	1	5	1	0	1	1	1	0	8	0	1	32	9	2	0	0	0	0	.161	.290	.478
2	Yankees	.200	October 1961	1	1.000	1	0	29	1	5	0	0	1	1	1	0	5	0	0	30	8	1	0	0	0	0	.172	.276	.476
3	Yankees	.212	October 1944	1	.000	0	1	32	2	6	2	1	0	2	1	0	4	1	0	34	10	3	1			1	.188	.313	.525
4	Yankees	.226	October 1972	5	.000	0	5	165	7	28	6	0	5	7	10	2	23	0	2	177	49	11	0	0	3	3	.170	.297	.523
5	Yankees	.228	October 2021	3	.333	1	2	95	6	17	2	1	1	6	5	1	28	0	0	101	24	4	0	0	0	3	.179	.253	.480
6	Yankees	.241	October 1914	7	.429	3	4	219	17	36	2	3	1	12	22	0	26	13		244	47	6	3				.164	.215	.455
7	Yankees	.248	October 2004	3	.333	1	2	93	5	17	4	0	1	5	6	2	21	0	0	101	24	5	0	0	1	4	.183	.258	.506
8	Yankees	.250	October 1990	3	.333	1	2	93	7	15	3	0	1	4	11	0	22	3	1	104	21	4	0	0	1	2	.161	.226	.476
9	Yankees	.253	October 1983	2	.500	1	1	72	5	10	3	0	1	4	11	0	10	2	0	83	16	4	0	0	0	2	.139	.222	.475
10	Highlanders	.258	September 1908	28	.357	10	18	900	61	196	18	5	2		43	6		37		946	230	25	30				.218	.256	.514
11	Highlanders	.260	August 1908	25	.240	6	19	795	57	168	24	7	0		49	3		42		839	206	31	27				.211	.259	.519
12	Yankees	.263	October 1922	1	.000	0	1	33	1	5	1	0	0	1	5	0	5	0	0	38	6	1	0				.152	.182	.445
13	Highlanders	.263	May 1907	22	.500	11	11	709	68	152	21	7	0		42	5		32		739	187	28	18				.214	.264	.527
14	Yankees	.264	October 1978	2	.500	1	1	66	7	13	4	0	2	7	6	0	9	2	0	72	23	6	0	0	0	1	.197	.348	.612
15	Yankees	.266	September 1966	23	.348	8	15	781	75	164	13	4	26	72	56	5	150	4	3	853	263	43	7	4	2	5	.210	.337	.603
16	Highlanders	.270	October 1911	5	.000	0	5	145	9	26	2	0	0	8	17	1	36	11		164	28	2	1				.179	.193	.463
17	Highlanders	.270	May 1905	26	.280	7	18	852	83	176	24	8	3	69	67	7	120	45		946	225	35	20				.207	.264	.534
18	Yankees	.273	June 2023	23	.478	11	12	746	88	155	37	2	29	83	59	9	181	9	4	818	283	68	0	4	2	17	.208	.379	.652
19	Yankees	.273	October 1967	1	1.000	1	0	30	4	6	1	0	2	3	3	0	5	3	0	33	13	3	0	0	0	0	.200	.433	.706
20	Yankees	.274	September 1967	27	.444	12	15	852	65	180	24	2	12	56	73	2	178	18	9	947	244	38	16	4	6	16	.211	.286	.560
21	Yankees	.275	May 1967	25	.360	9	16	806	75	159	24	2	18	66	83	4	177	6	3	903	241	44	8	2	5	19	.197	.299	.574
22	Yankees	.276	October 1974	2	.500	1	1	73	4	18	1	1	1	4	3	0	7	1	0	76	24	3	0	0	0	1	.247	.329	.605
23	Highlanders	.277	September 1907	29	.429	12	16	937	104	217	23	15	1		48	11	105	46		985	273	39	22				.232	.291	.568
24	Yankees	.278	April 1913	13	.154	2	11	415	32	87	13	4	0	24	33	6	77	16		463	108	17	9				.210	.260	.538
25	Yankees	.278	October 1938	2	.500	1	1	63	8	11	3	0	1	6	8	1	5	2		72	17	4	0				.175	.270	.548