Jimmie Foxx had the highest on-base percentage in the AL in 1939, with an on-base percentage of .464.

Interpreted as:

best obp with a minimum of 3.1 PA per team game by a player in the al in 1939

	NAME	OBP	SEASON	TM	G	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	GIDP	AVG	SLG	OPS	WRC	WRAA	WOBA	WRC+	BRAA
1	Jimmie Foxx J. Foxx	.464	1939	BSA	124	467	130	168	31	10	35	105	89	2	72	4	3	563	324	76	5	17	.360	.694	1.158	144	74.3	.507	181	63.5
2	George Selkirk G. Selkirk	.452	1939	NYY	128	418	103	128	17	4	21	101	103	8	49	12	5	537	216	42	8	3	.306	.517	.969	110	43.7	.444	151	38.1
3	Joe DiMaggio J. DiMaggio	.448	1939	NYY	120	462	108	176	32	6	30	126	52	4	20	3	0	524	310	68	6	11	.381	.671	1.119	129	64	.495	180	58.5
4	Charlie Keller C. Keller	.447	1939	NYY	111	398	87	133	21	6	11	83	81	0	49	6	3	490	199	38	11	4	.334	.500	.947	97	36.5	.436	146	31.4
5	Bob Johnson B. Johnson	.440	1939	PHA	150	544	115	184	30	9	23	114	99	0	59	15	5	653	301	62	10	12	.338	.553	.993	137	55.7	.449	150	45.6
6	Ted Williams T. Williams	.436	1939	BSA	149	565	131	185	44	11	31	145	107	2	64	2	1	677	344	86	3	10	.327	.609	1.045	150	66.1	.464	156	53.1
7	Luke Appling L. Appling	.430	1939	CWS	148	516	82	162	16	6	0	56	105	0	37	16	9	630	190	22	9	11	.314	.368	.798	99	21.1	.385	114	12.2
8	Charlie Gehringer C. Gehringer	.423	1939	DET	118	406	86	132	29	6	16	86	68	1	16	4	3	486	221	51	11	7	.325	.544	.967	97	36.7	.437	138	25.6
9	Hank Greenberg H. Greenberg	.420	1939	DET	138	500	111	156	42	7	33	113	91	2	95	8	3	604	311	82	11	8	.312	.622	1.042	132	56.8	.460	151	43
10	Joe Cronin J. Cronin	.407	1939	BSA	143	520	97	160	33	3	19	107	87	0	48	6	6	627	256	55	20	18	.308	.492	.899	112	34.5	.412	126	22.5
11	Hal Trosky Sr. H. Trosky Sr.	.405	1939	CLE	122	448	89	150	31	4	25	104	52	1	28	2	3	511	264	60	10	6	.335	.589	.994	105	41.2	.444	150	35.2
12	Red Rolfe R. Rolfe	.404	1939	NYY	152	648	139	213	46	10	14	80	81	1	41	7	6	731	321	70	1	6	.329	.495	.899	130	39.5	.411	131	31.9
13	Bill Dickey B. Dickey	.403	1939	NYY	128	480	98	145	23	3	24	105	77	4	37	5	0	565	246	50	4	9	.302	.513	.915	103	33.2	.416	135	27.3
14	Harlond Clift H. Clift	.402	1939	SLA	151	526	90	142	25	2	15	84	111	5	55	4	3	653	216	42	11	6	.270	.411	.813	102	21.3	.384	109	8
15	Buddy Lewis B. Lewis	.402	1939	WSH	140	536	87	171	23	16	10	75	72	2	27	10	9	629	256	49	19	7	.319	.478	.879	108	30.1	.403	128	24.3
16	Mike Kreevich M. Kreevich	.390	1939	CWS	145	541	85	175	30	8	5	77	59	0	40	23	10	622	236	43	22	14	.323	.436	.826	97	19.6	.383	112	10.7
17	Ben Chapman B. Chapman	.390	1939	CLE	149	545	101	158	31	9	6	82	87	2	30	18	6	654	225	46	20	19	.290	.413	.802	98	16.9	.376	110	9.3
18	Barney McCosky B. McCosky	.384	1939	DET	147	611	120	190	33	14	4	58	70	2	45	20	4	692	263	51	9	7	.311	.430	.814	104	18.6	.377	103	2.8
19	George McQuinn G. McQuinn	.383	1939	SLA	154	617	101	195	37	13	20	94	65	2	42	6	5	702	318	70	18	11	.316	.515	.898	122	35.2	.406	121	20.9
20	Bruce Campbell B. Campbell	.383	1939	CLE	130	450	84	129	23	13	8	72	67	3	48	7	6	527	202	44	7	6	.287	.449	.832	82	16.8	.383	114	10.6
21	Ken Keltner K. Keltner	.379	1939	CLE	154	587	84	191	35	11	13	97	51	0	41	6	6	648	287	59	10	15	.325	.489	.868	107	26.6	.394	121	19
22	Joe Kuhel J. Kuhel	.376	1939	CWS	139	546	107	164	24	9	15	56	64	2	51	18	5	623	251	48	11	7	.300	.460	.836	97	19.9	.383	113	11
23	Eric McNair E. McNair	.375	1939	CWS	129	479	62	155	18	5	7	82	38	1	41	17	9	528	204	30	10	13	.324	.426	.800	77	11.4	.370	105	3.9
24	Wally Moses W. Moses	.370	1939	PHA	115	437	68	134	28	7	3	33	44	0	23	7	4	486	185	38	5	4	.307	.423	.793	69	9.1	.367	102	1.6
25	Joe Gordon J. Gordon	.370	1939	NYY	151	567	92	161	32	5	28	111	75	2	57	11	10	648	287	65	4	15	.284	.506	.876	107	27.2	.396	123	20.4