The St. Louis Maroons have the best winning percentage by a team in a season, winning 83.2 percent of the time in 1884.

	TEAM	W%	SEASON	W	L	G	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	AVG	OBP	SLG	OPS
1	Maroons	.832	1884	94	19	114	4,285	887	1,251	259	41	32		181		542			4,466	1,688	332					.292		.394
2	White Stockings	.798	1880	67	17	86	3,135	538	876	164	39	4	378	104		217			3,239	1,130	207					.279		.360
3	White Stockings	.788	1876	52	14	66	2,748	624	926	131	32	8	441	70		45			2,818	1,145	171					.337		.417
4	White Stockings	.777	1885	87	25	113	4,093	834	1,079	184	75	54	606	340		429			4,433	1,575	313					.264		.385
5	Cubs	.763	1906	116	36	155	5,018	704	1,316	181	71	20	539	448	45	516	283		5,742	1,699	272	231				.262	.328	.339	.667
6	Gothams	.759	1885	85	27	112	4,029	691	1,085	150	82	16	464	221		312			4,250	1,447	248					.269		.359
7	Grays	.750	1884	84	28	114	4,093	665	987	153	43	21	404	300		469			4,393	1,289	217					.241		.315
8	Pirates	.741	1902	103	36	142	4,926	774	1,410	189	95	18	660	372	64	440	222		5,480	1,843	302	118				.286	.344	.374	.718
9	White Stockings	.726	1886	90	34	126	4,378	900	1,223	198	87	53	673	460		513	213		4,838	1,754	338					.279		.401
10	Pirates	.724	1909	110	42	154	5,128	701	1,332	218	92	25	585	479	36	511	185		5,860	1,809	335	217				.260	.327	.353	.680
11	Indians	.721	1954	111	43	156	5,222	746	1,368	188	39	156	714	637	23	668	30	33	6,048	2,102	383	107	59		114	.262	.341	.403	.744
12	Dodgers	.717	2020	43	17	60	2,042	349	523	97	6	118	327	228	30	471	29	8	2,315	986	221	3	12	7	46	.256	.338	.483	.821
13	Mariners	.716	2001	116	46	162	5,680	927	1,637	310	38	169	881	614	62	989	174	42	6,474	2,530	517	48	70	54	112	.288	.360	.445	.805
14	Yankees	.714	1927	110	44	155	5,354	976	1,644	291	103	158	907	642	22	610	90	64	6,222	2,615	552	204				.307	.384	.488	.872
15	Wolverines	.707	1886	87	36	126	4,501	829	1,260	176	81	53	636	374		426	194		4,875	1,757	310					.280		.390
16	Browns	.705	1885	79	33	112	3,972	677	979	132	57	17	450	234	49	282			4,255	1,276	206					.246	.297	.321	.618
17	Beaneaters	.705	1897	93	39	135	4,937	1,025	1,574	230	83	45	885	423	47	263	233		5,521	2,105	358	114				.319	.378	.426	.804
18	Athletics	.704	1931	107	45	153	5,377	858	1,544	311	64	118	798	528	35	543	25	23	6,018	2,337	493	78				.287	.355	.435	.789
19	Cubs	.704	1907	107	45	155	4,892	571	1,224	162	48	13	450	435	48	449	235		5,570	1,521	223	195				.250	.318	.311	.628
20	Yankees	.704	1998	114	48	162	5,643	965	1,625	290	31	207	907	653	57	1,025	153	63	6,444	2,598	528	32	59	34	145	.288	.364	.460	.825
21	Browns	.704	1887	95	40	138	5,048	1,131	1,550	261	78	39	862	442	67	342	581		5,557	2,084	378					.307	.371	.413	.783
22	Brown Stockings	.703	1876	45	19	64	2,478	386	642	73	27	2	264	59		63			2,537	775	102					.259		.313
23	Grays	.702	1879	59	25	85	3,392	612	1,003	142	55	12	405	91		172			3,483	1,291	209					.296		.381
24	Yankees	.702	1939	106	45	152	5,300	967	1,521	259	55	166	904	701	36	543	72	37	6,129	2,388	480	92			99	.287	.374	.451	.825
25	Metropolitans	.701	1884	75	32	112	4,012	734	1,052	155	64	22		203	35	315			4,250	1,401	241					.262	.304	.349	.653