best single season mlb record based on winning percentages in modern era

Since 1900, the Chicago Cubs have the best record by a team in a season, with a record of 116-36 in 1906.

	TEAM	REC	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	Cubs	116-36	.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
2	Pirates	103-36	.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
3	Pirates	110-42	.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
4	Indians	111-43	.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
5	Dodgers	43-17	.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
6	Mariners	116-46	.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
7	Yankees	110-44	.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
8	Cubs	107-45	.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
9	Athletics	107-45	.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
10	Yankees	114-48	.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
11	Yankees	106-45	.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
12	Giants	106-47	.693	1904	106	47	158	5,150	744	1,347	202	65	31	564	434	79	459	283		5,828	1,772	298	165				.262	.328	.344	.673
13	Yankees	107-47	.695	1932	107	47	156	5,476	1,002	1,564	279	82	160	954	765	27	526	77	66	6,344	2,487	521	76				.286	.376	.454	.830
14	Indians	100-44	.694	1995	100	44	144	5,028	840	1,461	279	23	207	803	542	35	766	132	53	5,684	2,407	509	31	48	40	128	.291	.361	.479	.839
15	Athletics	104-46	.693	1929	104	46	151	5,204	901	1,537	288	75	122	845	540	29	440	63	42	5,987	2,341	485	214				.295	.365	.450	.815
16	Red Sox	105-47	.691	1912	105	47	154	5,071	799	1,404	269	84	29	654	565	45	586	185	182	5,872	1,928	382	191				.277	.355	.380	.735
17	Cardinals	106-48	.688	1942	106	48	156	5,422	755	1,454	282	69	60	680	551	22	505	71		6,125	2,054	411	130			90	.268	.338	.379	.717
18	Giants	105-48	.686	1905	105	48	155	5,094	778	1,392	191	88	39	642	517	90	497	291		5,839	1,876	318	138				.273	.351	.368	.719
19	Reds	96-44	.686	1919	96	44	140	4,577	578	1,204	135	83	20	489	405	33	368	143		5,214	1,565	238	199				.263	.327	.342	.669
20	Dodgers	111-51	.685	2022	111	51	162	5,526	847	1,418	325	31	212	812	607	56	1,374	98	18	6,245	2,441	568	3	53	22	85	.257	.333	.442	.775
21	Giants	103-48	.682	1912	103	48	154	5,067	823	1,451	231	89	47	716	514	69	497	319		5,802	2,001	367	152				.286	.360	.395	.755
22	Dodgers	105-49	.682	1953	105	49	155	5,373	955	1,529	274	59	208	887	655	35	686	90	47	6,138	2,545	541	75			115	.285	.366	.474	.840
23	Cardinals	105-49	.682	1944	105	49	157	5,474	772	1,507	274	59	100	722	543	27	471	37		6,168	2,199	433	124			96	.275	.344	.402	.745
24	Cardinals	105-49	.682	1943	105	49	157	5,435	679	1,515	259	72	70	638	428	19	437	40		6,055	2,128	401	173			92	.279	.334	.392	.725
25	Athletics	102-48	.680	1910	102	48	155	5,154	671	1,373	191	105	19	541	409	47	573	207		5,809	1,831	315	199				.266	.326	.355	.681