The Houston Astros had the worst winning percentage by a team in 2011, winning 34.6 percent of the time.

	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	Astros	.346	2011	56	106	162	5,598	615	1,442	309	28	95	579	401	46	1,164	118	33	6,148	2,092	432	66	37	34	111	.258	.311	.374	.684
2	Twins	.389	2011	63	99	162	5,487	619	1,357	259	25	103	572	440	37	1,048	92	39	6,020	1,975	387	31	25	24	115	.247	.306	.360	.666
3	Mariners	.414	2011	67	95	162	5,421	556	1,263	253	22	109	534	435	37	1,280	125	40	5,972	1,887	384	38	41	33	82	.233	.292	.348	.640
4	Orioles	.426	2011	69	93	162	5,585	708	1,434	273	13	191	684	452	52	1,120	81	25	6,156	2,306	477	24	43	24	154	.257	.316	.413	.729
5	Cubs	.438	2011	71	91	162	5,549	654	1,423	285	36	148	610	425	59	1,202	69	23	6,128	2,224	469	60	35	35	123	.256	.314	.401	.715
6	Royals	.438	2011	71	91	162	5,672	730	1,560	325	41	129	705	442	39	1,006	153	58	6,265	2,354	495	55	57	37	121	.275	.329	.415	.744
7	Padres	.438	2011	71	91	162	5,417	593	1,284	247	42	91	563	501	48	1,320	170	44	6,068	1,888	380	55	47	42	105	.237	.305	.349	.653
8	Pirates	.444	2011	72	90	162	5,421	610	1,325	277	35	107	580	489	34	1,308	108	52	6,063	1,993	419	75	44	31	123	.244	.309	.368	.676
9	Marlins	.444	2011	72	90	162	5,508	625	1,358	274	30	149	596	542	51	1,244	95	41	6,232	2,139	453	89	42	38	111	.247	.318	.388	.706
10	Rockies	.451	2011	73	89	162	5,544	735	1,429	274	40	163	697	555	57	1,201	118	42	6,275	2,272	477	75	44	54	112	.258	.329	.410	.739
11	Athletics	.457	2011	74	88	162	5,452	645	1,330	280	29	114	612	509	50	1,094	117	43	6,102	2,010	423	34	57	20	119	.244	.311	.369	.680
12	Mets	.475	2011	77	85	162	5,600	718	1,477	309	39	108	676	571	51	1,085	130	35	6,335	2,188	456	65	48	56	112	.264	.335	.391	.725
13	Reds	.488	2011	79	83	162	5,612	735	1,438	264	19	183	697	535	63	1,250	97	50	6,328	2,289	466	78	40	52	98	.256	.326	.408	.734
14	White Sox	.488	2011	79	83	162	5,502	654	1,387	252	16	154	625	475	84	989	81	53	6,159	2,133	422	52	46	31	125	.252	.319	.388	.706
15	Indians	.494	2011	80	82	162	5,509	704	1,380	290	26	154	671	494	65	1,269	89	42	6,142	2,184	470	31	43	30	111	.250	.317	.396	.714
16	Nationals	.497	2011	80	81	161	5,441	624	1,319	257	22	154	594	470	65	1,323	106	38	6,090	2,082	433	82	32	40	103	.242	.309	.383	.691
17	Blue Jays	.500	2011	81	81	162	5,559	743	1,384	285	34	186	704	525	48	1,184	131	52	6,210	2,295	505	31	47	41	108	.249	.317	.413	.730
18	Dodgers	.509	2011	82	79	161	5,436	644	1,395	237	28	117	613	498	45	1,087	126	40	6,093	2,039	382	71	43	61	101	.257	.322	.375	.697
19	Giants	.531	2011	86	76	162	5,486	570	1,327	282	24	121	534	448	52	1,122	85	51	6,091	2,020	427	62	43	47	117	.242	.303	.368	.671
20	Angels	.531	2011	86	76	162	5,513	667	1,394	289	34	155	629	442	51	1,086	135	52	6,088	2,216	478	50	32	33	126	.253	.313	.402	.714
21	Braves	.549	2011	89	73	162	5,528	641	1,345	244	16	173	606	504	28	1,260	77	44	6,165	2,140	433	75	30	45	113	.243	.308	.387	.695
22	Cardinals	.556	2011	90	72	162	5,532	762	1,513	308	22	162	726	542	44	978	57	39	6,242	2,351	492	84	40	64	169	.273	.341	.425	.766
23	Red Sox	.556	2011	90	72	162	5,710	875	1,600	352	35	203	842	578	50	1,108	102	42	6,410	2,631	590	22	50	52	136	.280	.349	.461	.810
24	Rays	.562	2011	91	71	162	5,436	707	1,324	273	37	172	674	571	73	1,193	155	62	6,152	2,187	482	37	35	31	101	.244	.322	.402	.724
25	Diamondbacks	.580	2011	94	68	162	5,421	731	1,357	293	37	172	702	531	61	1,249	133	55	6,096	2,240	502	50	33	55	82	.250	.322	.413	.736