orioles single season obp leaders with over 249 ab since 1965

Since 1965, Ken Singleton has the highest on-base percentage for the Orioles with >249 at-bats in a season, with an on-base percentage of .438 in 1977.

	NAME	OBP	AB	SEASON	TM	G	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	AVG	SLG	OPS	WRC	WRAA	WOBA	WRC+	BRAA
1	Ken Singleton K. Singleton	.438	536	1977	BAL	152	90	176	24	0	24	99	107	2	101	0	1	651	272	48	0	6	13	15	.328	.507	.945	123	46.9	.414	166	50.9
2	Merv Rettenmund M. Rettenmund	.422	491	1971	BAL	141	81	156	23	4	11	75	87	4	60	15	6	589	220	38	4	3	2	13	.318	.448	.870	98	37.6	.398	151	33.1
3	Melvin Mora M. Mora	.419	550	2004	BAL	140	111	187	41	0	27	104	66	11	95	11	6	636	309	68	6	3	0	10	.340	.562	.981	128	49	.421	159	48.2
4	Melvin Mora M. Mora	.418	344	2003	BAL	96	68	109	17	1	15	48	49	12	71	6	3	413	173	33	6	2	0	3	.317	.503	.921	77	25.9	.403	151	26.4
5	Chris Hoiles C. Hoiles	.416	419	1993	BAL	126	80	130	28	0	29	82	69	9	94	1	1	503	245	57	3	3	4	10	.310	.585	1.001	103	43.2	.433	166	40.8
6	Frank Robinson F. Robinson	.415	539	1969	BAL	148	111	166	19	5	32	100	88	13	62	9	3	643	291	56	0	3	11	12	.308	.540	.955	122	53	.424	166	48.9
7	Ken Singleton K. Singleton	.415	586	1975	BAL	155	88	176	37	4	15	55	118	1	82	3	5	714	266	56	3	6	12	9	.300	.454	.869	118	39.3	.394	152	41.7
8	John Lowenstein J. Lowenstein	.415	322	1982	BAL	122	69	103	15	2	24	66	54	1	59	7	6	384	194	41	3	4	10	6	.320	.602	1.017	78	34.8	.436	173	33.3
9	Don Buford D. Buford	.413	449	1971	BAL	122	99	130	19	4	19	54	89	7	62	15	7	549	214	42	2	2	15	2	.290	.477	.890	91	35	.397	151	30.8
10	Will Clark W. Clark	.413	256	2000	BAL	79	49	77	15	1	9	28	47	4	45	4	2	310	121	25	0	3	3	4	.301	.473	.886	54	13	.389	131	13.2
11	Boog Powell B. Powell	.412	526	1970	BAL	154	82	156	28	0	35	114	104	5	80	1	1	643	289	63	0	8	18	14	.297	.549	.962	121	48.1	.415	160	45.5
12	Roberto Alomar R. Alomar	.411	588	1996	BAL	153	132	193	43	4	22	94	90	1	65	17	6	699	310	69	8	12	10	14	.328	.527	.938	130	39.5	.402	135	33.5
13	Frank Robinson F. Robinson	.410	576	1966	BAL	155	122	182	34	2	49	122	87	10	90	8	5	680	367	85	0	7	11	24	.316	.637	1.047	146	73.4	.447	195	71.4
14	Eddie Murray E. Murray	.410	588	1984	BAL	162	97	180	26	3	29	110	107	2	87	10	2	705	299	58	0	8	25	9	.306	.509	.918	122	43.8	.398	150	41.6
15	Ken Singleton K. Singleton	.409	502	1978	BAL	149	67	147	21	2	20	81	98	2	94	0	0	608	232	43	4	2	5	14	.293	.462	.871	101	35.4	.395	154	36.6
16	Randy Milligan R. Milligan	.408	362	1990	BAL	109	64	96	20	1	20	60	88	2	68	6	3	456	178	41	0	4	3	11	.265	.492	.900	80	29.1	.401	156	29
17	David Segui D. Segui	.406	292	2001	BAL	82	48	88	18	1	10	46	49	4	61	1	1	347	138	29	0	2	5	4	.301	.473	.879	59	15.5	.380	138	16.5
18	Nick Markakis N. Markakis	.406	595	2008	BAL	157	106	182	48	1	20	87	99	2	113	10	7	697	292	69	0	1	7	10	.306	.491	.897	120	36.6	.392	138	32.9
19	Don Buford D. Buford	.406	504	1970	BAL	144	99	137	15	2	17	66	109	8	55	16	8	629	207	34	3	5	8	1	.272	.411	.816	97	25.8	.372	131	23.2
20	Ken Singleton K. Singleton	.405	570	1979	BAL	159	93	168	29	1	35	111	109	1	118	3	1	688	304	65	1	7	16	16	.295	.533	.938	125	44.6	.406	153	44.9
21	Brady Anderson B. Anderson	.404	564	1999	BAL	150	109	159	28	5	24	81	96	24	105	36	7	692	269	57	1	7	7	6	.282	.477	.881	117	27.3	.386	130	27.5
22	Frank Robinson F. Robinson	.403	479	1967	BAL	129	83	149	23	7	30	94	71	7	84	2	3	563	276	60	0	6	14	10	.311	.576	.979	108	51.6	.426	183	49.4
23	Harold Baines H. Baines	.403	385	1995	BAL	127	60	115	19	1	24	63	70	0	45	0	2	459	208	44	0	4	13	17	.299	.540	.943	83	26.1	.401	138	22.8
24	Albert Belle A. Belle	.400	610	1999	BAL	161	108	181	36	1	37	117	101	7	82	17	3	722	330	74	0	4	15	19	.297	.541	.941	131	37.2	.400	139	37.5
25	Al Bumbry A. Bumbry	.398	356	1973	BAL	110	73	120	15	11	7	34	34	3	49	23	10	395	178	33	1	1	0	5	.337	.500	.898	69	25.4	.403	157	25.6