Between the 1945 and 1954 seasons, the Baltimore Orioles had the worst winning percentage by a team, winning 39.1 percent of the time.

	TEAM	W%	W	L	G	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	GIDP	AVG	OBP	SLG	OPS
1	Orioles	.391	600	936	1,545	52,365	6,056	13,145	2,180	437	855	5,656	5,481	182	6,631	369	137	58,998	18,764	3,472	926	44	1,293	.251	.324	.358	.682
2	Pirates	.407	627	912	1,548	52,528	6,500	13,382	2,044	498	1,064	6,035	5,612	239	6,336	452	120	59,226	19,614	3,606	789	58	1,197	.255	.329	.373	.703
3	Athletics	.426	655	881	1,548	52,311	6,355	13,274	2,158	446	785	5,902	6,092	236	5,527	389	132	59,593	18,679	3,389	923	31	1,326	.254	.334	.357	.691
4	Redlegs	.437	672	866	1,544	52,818	6,226	13,383	2,249	359	1,010	5,813	4,771	201	5,935	457	132	58,666	19,380	3,618	825	51	1,133	.253	.317	.367	.684
5	Senators	.444	682	855	1,546	52,455	6,167	13,264	2,128	554	571	5,742	5,760	243	5,771	573	132	59,295	18,213	3,253	795	42	1,279	.253	.329	.347	.677
6	Cubs	.459	706	832	1,547	52,965	6,336	13,737	2,200	488	1,035	5,893	4,820	250	6,351	480	122	58,864	20,018	3,723	789	40	1,213	.259	.324	.378	.702
7	Phillies	.476	733	807	1,548	52,723	6,352	13,660	2,207	480	952	5,898	5,010	213	5,795	478	117	58,838	19,683	3,639	837	55	1,171	.259	.326	.373	.699
8	White Sox	.479	734	799	1,546	52,393	6,293	13,572	2,029	494	637	5,845	5,644	316	5,394	705	221	59,343	18,500	3,160	937	53	1,323	.259	.334	.353	.688
9	Tigers	.504	776	763	1,557	53,106	6,860	13,921	2,287	446	973	6,427	6,160	194	5,529	403	151	60,460	20,019	3,706	959	41	1,398	.262	.341	.377	.718
10	Braves	.524	804	731	1,550	53,039	6,982	13,935	2,361	394	1,111	6,524	5,562	254	5,872	580	126	59,925	20,417	3,866	1,026	44	1,220	.263	.335	.385	.720
11	Giants	.528	814	727	1,548	52,903	7,364	13,869	1,964	467	1,592	6,936	5,590	313	5,833	395	109	59,633	21,543	4,023	775	52	1,139	.262	.336	.407	.743
12	Red Sox	.558	860	680	1,551	53,475	7,769	14,469	2,500	429	1,139	7,289	6,717	238	6,014	434	143	61,279	21,244	4,068	796	53	1,415	.271	.354	.397	.751
13	Cardinals	.561	865	676	1,552	53,580	7,376	14,430	2,573	552	1,020	6,869	5,684	289	5,319	349	130	60,415	21,167	4,145	796	66	1,197	.269	.342	.395	.737
14	Indians	.580	888	644	1,546	52,524	7,077	13,774	2,149	465	1,291	6,689	5,928	231	6,343	404	136	59,678	20,726	3,905	936	59	1,242	.262	.339	.395	.734
15	Dodgers	.607	937	607	1,555	53,426	8,103	14,441	2,438	518	1,363	7,491	6,459	298	6,115	888	205	61,232	22,004	4,319	990	59	1,193	.270	.352	.412	.764
16	Yankees	.618	949	586	1,539	52,412	7,885	14,070	2,197	603	1,298	7,382	6,366	309	5,799	460	166	59,988	21,367	4,098	854	47	1,159	.268	.351	.408	.758