Between the 1936 and 1939 seasons, the St. Louis Browns had the worst winning percentage by a team, winning 32.8 percent of the time.

	TEAM	W%	W	L	G	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	PA	TB	XBH	SH	GIDP	AVG	OBP	SLG	OPS
1	Browns	.328	201	411	623	21,656	3,007	6,026	1,141	196	333	2,852	2,286	73	2,271	191	24,410	8,558	1,670	395	121	.278	.349	.395	.744
2	Phillies	.337	205	403	612	21,214	2,553	5,679	973	152	295	2,363	1,773	58	2,219	201	23,453	7,841	1,420	408	133	.268	.326	.370	.695
3	Athletics	.354	215	393	615	21,139	2,850	5,689	1,043	237	362	2,665	2,216	61	2,270	279	23,776	8,292	1,642	360	121	.269	.340	.392	.732
4	Dodgers	.463	282	327	619	21,361	2,690	5,661	1,011	232	209	2,450	2,034	91	2,295	249	23,861	7,763	1,452	375	130	.265	.332	.363	.695
5	Bees	.476	290	319	614	21,138	2,343	5,421	805	164	240	2,181	1,708	93	2,331	158	23,351	7,274	1,209	412	119	.256	.315	.344	.659
6	Senators	.484	295	314	616	21,819	3,162	6,245	1,065	319	238	2,929	2,288	76	1,739	324	24,538	8,662	1,622	355	103	.286	.356	.397	.753
7	Reds	.505	309	303	616	21,392	2,824	5,793	959	249	363	2,634	1,713	125	2,226	186	23,651	8,339	1,571	421	110	.271	.328	.390	.718
8	White Sox	.522	317	290	611	21,221	3,164	5,965	1,021	243	258	2,924	2,327	80	1,857	305	24,078	8,246	1,522	450	108	.281	.354	.389	.743
9	Pirates	.530	324	287	615	21,710	2,881	6,110	1,032	292	235	2,657	1,942	77	1,811	160	24,137	8,431	1,559	408	128	.281	.343	.388	.731
10	Cardinals	.541	331	281	623	21,988	3,088	6,240	1,216	263	371	2,876	1,714	74	2,204	246	24,186	9,095	1,850	410	116	.284	.338	.414	.751
11	Red Sox	.546	331	275	611	21,274	3,388	6,100	1,142	239	408	3,179	2,425	77	1,986	231	24,240	8,944	1,789	464	146	.287	.362	.420	.782
12	Tigers	.547	337	279	619	21,576	3,567	6,170	1,131	236	505	3,327	2,614	94	2,346	326	24,662	9,288	1,872	378	125	.286	.366	.430	.796
13	Indians	.547	336	278	620	21,671	3,382	6,210	1,252	326	424	3,136	2,189	67	2,199	299	24,298	9,386	2,002	371	110	.287	.354	.433	.787
14	Giants	.572	347	260	609	21,162	2,882	5,832	909	163	449	2,687	1,806	131	1,971	133	23,508	8,414	1,521	409	153	.276	.336	.398	.734
15	Cubs	.575	353	261	618	21,384	3,003	5,924	1,033	242	328	2,813	2,074	117	1,987	249	24,059	8,425	1,603	484	124	.277	.344	.394	.738
16	Yankees	.670	409	201	621	21,788	3,977	6,231	1,139	274	696	3,740	2,862	142	2,360	300	25,073	10,006	2,109	281	99	.286	.372	.459	.832