Between the 2000 and 2021 seasons, the Los Angeles Dodgers had the highest winning percentage by a team in a season, winning 71.7 percent of the time in 2020.

	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	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
2	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
3	Rays	.667	2020	40	20	60	1,975	289	470	105	12	80	274	243	28	608	48	9	2,260	839	197	0	14	9	38	.238	.328	.425	.753
4	Red Sox	.667	2018	108	54	162	5,623	876	1,509	355	31	208	829	569	55	1,253	125	31	6,302	2,550	594	7	48	38	130	.268	.339	.453	.792
5	Giants	.660	2021	107	55	162	5,462	804	1,360	271	25	241	768	602	64	1,461	66	14	6,194	2,404	537	36	30	45	117	.249	.329	.440	.769
6	Astros	.660	2019	107	55	162	5,613	920	1,538	323	28	288	891	645	66	1,166	67	27	6,391	2,781	639	10	57	17	146	.274	.352	.495	.848
7	Dodgers	.654	2021	106	56	162	5,445	830	1,330	247	24	237	799	613	104	1,408	65	17	6,239	2,336	508	32	45	36	96	.244	.330	.429	.759
8	Dodgers	.654	2019	106	56	162	5,493	886	1,414	302	20	279	861	607	81	1,356	57	10	6,281	2,593	601	55	45	47	100	.257	.338	.472	.810
9	Cardinals	.648	2004	105	57	162	5,555	855	1,544	319	24	214	817	548	51	1,085	111	47	6,297	2,553	557	73	70	64	121	.278	.344	.460	.804
10	Dodgers	.642	2017	104	58	162	5,408	770	1,347	312	20	221	730	649	64	1,380	77	28	6,190	2,362	553	31	38	41	119	.249	.334	.437	.771
11	Cubs	.640	2016	103	58	162	5,503	808	1,409	293	30	199	767	656	96	1,339	66	34	6,334	2,359	522	42	37	45	107	.256	.343	.429	.772
12	Yankees	.640	2002	103	58	161	5,601	897	1,540	314	12	223	857	640	72	1,171	100	38	6,377	2,547	549	23	41	48	150	.275	.354	.455	.809
13	Yankees	.636	2019	103	59	162	5,583	943	1,493	290	17	306	904	569	49	1,437	55	22	6,244	2,735	613	10	33	18	113	.267	.339	.490	.829
14	Astros	.636	2018	103	59	162	5,453	797	1,390	278	18	205	763	565	61	1,197	71	26	6,138	2,319	501	14	45	19	156	.255	.329	.425	.754
15	Yankees	.636	2009	103	59	162	5,660	915	1,604	325	21	244	881	663	54	1,014	111	28	6,447	2,703	590	31	39	35	144	.283	.362	.478	.839
16	Athletics	.636	2002	103	59	162	5,558	800	1,450	279	28	205	772	609	68	1,008	46	20	6,291	2,400	512	20	36	37	128	.261	.339	.432	.771
17	Braves	.631	2002	101	59	161	5,495	708	1,428	280	25	164	669	558	54	1,028	76	39	6,223	2,250	469	67	49	68	147	.260	.331	.409	.741
18	Indians	.630	2017	102	60	162	5,511	818	1,449	333	29	212	780	604	50	1,153	88	23	6,233	2,476	574	23	45	30	125	.263	.339	.449	.788
19	Phillies	.630	2011	102	60	162	5,579	713	1,409	258	38	153	693	539	56	1,024	96	24	6,277	2,202	449	65	38	52	108	.253	.323	.395	.717
20	Athletics	.630	2001	102	60	162	5,573	884	1,469	334	22	199	835	640	88	1,021	68	29	6,385	2,444	555	25	59	57	131	.264	.345	.439	.784
21	Twins	.623	2019	101	61	162	5,732	939	1,547	318	23	307	906	525	81	1,334	28	21	6,389	2,832	648	10	41	21	101	.270	.338	.494	.832
22	Astros	.623	2017	101	61	162	5,611	896	1,581	346	20	238	854	509	70	1,087	98	42	6,262	2,681	604	11	61	27	139	.282	.346	.478	.823
23	Yankees	.623	2004	101	61	162	5,527	897	1,483	281	20	242	863	670	80	982	84	33	6,364	2,530	543	37	50	40	157	.268	.353	.458	.811
24	Braves	.623	2003	101	61	162	5,670	907	1,608	321	31	235	872	545	49	933	68	22	6,378	2,696	587	65	49	46	124	.284	.349	.475	.824
25	Yankees	.623	2003	101	61	163	5,605	877	1,518	304	14	230	845	684	81	1,042	98	33	6,430	2,540	548	25	35	54	154	.271	.356	.453	.810