Between the 1920 and 1929 seasons, Babe Ruth had the best on-base percentage, with an on-base percentage of .488.

Interpreted as:

best obp with a minimum of 1.55 PA per team game by an MLB player 1920s

	NAME	OBP	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	.488	1,399	4,884	1,365	1,734	314	82	467	1,338	1,240	27	795	88		6,224	3,613	863	73	.355	.740	1.228	1701	932.6	.535	206	884.9
2	Rogers Hornsby R. Hornsby	.460	1,430	5,451	1,195	2,085	405	115	250	1,153	753	24	431	74		6,389	3,470	770	161	.382	.637	1.096	1531	739.3	.490	186	714.6
3	Joe Jackson J. Jackson	.444	146	570	105	218	42	20	12	121	56	7	14	9	12	649	336	74	16	.382	.589	1.033	141	67.4	.474	167	56.5
4	Tristram Speaker T. Speaker	.441	1,170	4,226	830	1,496	397	74	72	726	636	26	104	58		5,034	2,257	543	146	.354	.534	.976	1023	405.6	.447	151	343.2
5	Lou Gehrig L. Gehrig	.436	767	2,746	631	919	206	72	146	635	480	15	351	30		3,321	1,707	424	80	.335	.622	1.058	743	327.2	.470	170	313.1
6	Jimmie Foxx J. Foxx	.436	364	1,088	241	372	61	25	49	222	178	4	131	15		1,301	630	135	31	.342	.579	1.015	279	113.6	.454	160	104.1
7	Eddie Collins E. Collins	.436	1,107	3,853	684	1,333	200	55	22	520	592	21	99	180		4,646	1,709	277	180	.346	.444	.879	824	252.6	.415	133	206.1
8	Harry Heilmann H. Heilmann	.433	1,417	5,285	962	1,924	397	101	142	1,131	615	25	324	70		6,115	2,949	640	190	.364	.558	.991	1266	508.8	.450	153	441
9	Ty Cobb T. Cobb	.431	1,105	4,133	830	1,476	293	85	50	727	512	28	145	128		4,791	2,089	428	118	.357	.505	.937	919	328.7	.432	142	275.3
10	Paul Waner P. Waner	.431	602	2,357	488	840	170	74	38	396	292	15	73	37		2,727	1,272	282	63	.356	.540	.970	546	206.5	.441	149	175.1
11	Max Bishop M. Bishop	.420	690	2,381	481	646	112	20	15	189	590	19	216	28		3,047	843	147	57	.271	.354	.774	457	74.8	.379	110	40.1
12	Johnny Bassler J. Bassler	.420	767	2,240	245	690	98	15	1	313	422	9	73	10		2,763	821	114	92	.308	.367	.786	418	72.9	.381	112	44.1
13	Mel Ott M. Ott	.414	391	1,203	237	388	72	9	61	251	179	8	92	12		1,414	661	142	24	.323	.549	.963	279	99.1	.433	143	87.1
14	Riggs Stephenson R. Stephenson	.413	839	2,901	488	987	220	41	49	510	330	32	165	42		3,335	1,436	310	72	.340	.495	.908	605	189.2	.417	136	161.2
15	Ray Grimes R. Grimes	.413	433	1,537	269	505	101	25	27	263	204	17	133	21		1,788	737	153	30	.329	.480	.892	316	93.4	.412	135	81.7
16	Al Wingo A. Wingo	.406	478	1,267	216	391	86	16	9	189	207	1	107	23		1,512	536	111	37	.309	.423	.829	241	52.2	.390	116	34.6
17	Lu Blue L. Blue	.405	1,230	4,516	897	1,324	248	87	39	548	820	33	311	109		5,514	1,863	374	145	.293	.413	.818	862	171.2	.386	115	112
18	Ross Youngs R. Youngs	.405	953	3,638	664	1,187	187	75	39	523	454	24	289	118		4,212	1,641	301	96	.326	.451	.856	693	174.5	.399	133	171.8
19	Wally Schang W. Schang	.404	1,036	3,057	443	908	170	46	41	428	502	48	278	52		3,698	1,293	257	91	.297	.423	.827	585	128.7	.390	118	86.2
20	Chuck Klein C. Klein	.404	213	869	167	310	59	10	54	179	68	1	83	5		954	551	123	16	.357	.634	1.038	207	83.7	.456	145	61.3
21	Jack Fournier J. Fournier	.401	1,059	3,748	621	1,213	186	69	121	657	424	61	256	78		4,340	1,900	376	107	.324	.507	.908	778	243.1	.416	144	240.9
22	Ken Williams K. Williams	.400	1,249	4,388	805	1,428	265	68	190	863	522	24	237	142		5,076	2,399	523	142	.325	.547	.947	961	335.4	.429	137	256.2
23	Joe Harris J. Harris	.399	794	2,481	391	782	163	59	46	405	322	26	134	23		2,906	1,201	268	77	.315	.484	.884	499	138.3	.407	129	111.7
24	Kiki Cuyler K. Cuyler	.399	797	3,033	618	1,005	169	81	70	493	297	45	341	210		3,465	1,546	320	90	.331	.510	.909	620	185.3	.414	133	154.7
25	Joe Sewell J. Sewell	.399	1,404	5,268	813	1,698	358	57	30	820	613	60	96	70		6,162	2,260	445	221	.322	.429	.828	967	197.1	.388	115	127.6