Babe Ruth had the best on-base percentage in the AL in 1931, with an on-base percentage of .495.

Interpreted as:

best obp with a minimum of 3.1 PA per team game by a player in the al in 1931

	NAME	OBP	SEASON	TM	G	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	AVG	SLG	OPS	WRC	WRAA	WOBA	WRC+	BRAA
1	Babe Ruth B. Ruth	.495	1931	NYY	145	534	149	199	31	3	46	162	128	1	51	5	4	663	374	80	0	.373	.700	1.195	181	98.6	.525	206	95.1
2	Ed Morgan E. Morgan	.451	1931	CLE	131	462	87	162	33	4	11	86	83	1	46	4	5	552	236	48	6	.351	.511	.961	114	45.4	.442	148	35.6
3	Lou Gehrig L. Gehrig	.446	1931	NYY	155	619	163	211	31	15	46	185	117	0	56	17	12	738	410	92	2	.341	.662	1.108	179	87.7	.488	184	83.8
4	Al Simmons A. Simmons	.444	1931	PHA	128	513	105	200	37	13	22	128	47	3	45	3	3	563	329	72	0	.390	.641	1.085	135	65.1	.484	176	57.9
5	Lu Blue L. Blue	.430	1931	CWS	155	589	119	179	23	15	1	62	127	3	60	13	3	725	235	39	6	.304	.399	.829	122	32.2	.395	127	26.6
6	Max Bishop M. Bishop	.426	1931	PHA	130	497	115	146	30	4	5	37	112	2	51	3	1	614	199	39	3	.294	.400	.826	103	26.8	.394	123	19
7	Mickey Cochrane M. Cochrane	.423	1931	PHA	122	459	87	160	31	6	17	89	56	3	21	2	3	521	254	54	3	.349	.553	.976	107	42.6	.441	151	36
8	Goose Goslin G. Goslin	.412	1931	SLA	151	591	114	194	42	10	24	105	80	4	41	9	6	675	328	76	0	.328	.555	.967	136	52	.435	144	40.1
9	Earl Averill E. Averill	.404	1931	CLE	155	627	140	209	36	10	32	143	68	6	38	9	9	701	361	78	0	.333	.576	.979	143	55.9	.439	146	43.5
10	Earl Webb E. Webb	.404	1931	BSA	151	589	96	196	67	3	14	103	70	0	51	2	2	660	311	84	1	.333	.528	.932	125	43.8	.422	142	37.8
11	Dale Alexander D. Alexander	.401	1931	DET	135	517	75	168	47	3	3	87	64	2	35	5	8	583	230	53	0	.325	.445	.846	97	25	.393	120	16.1
12	Ben Chapman B. Chapman	.396	1931	NYY	149	600	120	189	28	11	17	122	75	5	77	61	23	686	290	56	6	.315	.483	.879	120	34.8	.403	134	31.1
13	Earle Combs E. Combs	.394	1931	NYY	138	563	120	179	31	13	5	58	68	3	34	11	3	636	251	49	2	.318	.446	.840	104	25.2	.389	125	21.8
14	Joe Cronin J. Cronin	.391	1931	WSH	156	611	103	187	44	13	12	126	81	4	52	10	9	700	293	69	4	.306	.480	.870	120	33.1	.398	128	26.8
15	Joe Sewell J. Sewell	.390	1931	NYY	130	484	102	146	22	1	6	64	61	9	8	1	1	571	188	29	17	.302	.388	.778	84	13.5	.369	114	10.4
16	John Stone J. Stone	.388	1931	DET	147	584	86	191	28	11	10	78	56	2	48	13	13	647	271	49	5	.327	.464	.852	107	26.9	.391	120	17.1
17	Willie Kamm W. Kamm	.384	1931	TOT	132	469	77	136	35	5	0	75	71	1	19	14	10	553	181	40	12	.290	.386	.770	79	11	.364	103	1.9
18	Jimmie Foxx J. Foxx	.380	1931	PHA	139	515	93	150	32	10	30	120	73	1	84	4	3	593	292	72	4	.291	.567	.947	113	39.3	.422	140	31.8
19	Bill Dickey B. Dickey	.378	1931	NYY	130	477	65	156	17	10	6	78	39	0	20	2	1	523	211	33	7	.327	.442	.820	81	16.1	.378	119	13.3
20	Lyn Lary L. Lary	.376	1931	NYY	155	610	100	171	35	9	10	107	88	6	54	13	10	712	254	54	8	.280	.416	.793	106	17.5	.370	114	13.7
21	Tony Lazzeri T. Lazzeri	.371	1931	NYY	135	484	67	129	27	7	8	83	79	1	80	18	9	568	194	42	4	.267	.401	.771	80	10.2	.362	109	7.2
22	Fred Schulte F. Schulte	.369	1931	SLA	134	553	100	168	32	7	9	65	56	1	49	6	8	613	241	48	3	.304	.436	.805	92	15.7	.371	106	4.8
23	Sam West S. West	.369	1931	WSH	132	526	77	175	43	13	3	91	30	0	37	6	8	559	253	59	3	.333	.481	.850	90	20.8	.386	121	15.7
24	Mule Haas M. Haas	.366	1931	PHA	102	440	82	142	29	7	8	56	30	0	29	0	0	489	209	44	19	.323	.475	.841	78	17	.383	116	10.8
25	Joe Vosmik J. Vosmik	.363	1931	CLE	149	591	80	189	36	14	7	117	38	2	30	7	7	640	274	57	9	.320	.464	.827	98	19.2	.377	109	7.8