Between the 1938 and 1941 seasons, the Philadelphia Phillies had the worst winning percentage by a team, winning 30.1 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	Phillies	.301	183	425	611	20,695	2,098	5,161	833	142	228	1,939	1,730	57	2,115	175	22,889	6,962	1,203	407	390	.249	.309	.336	.645
2	Athletics	.369	226	386	615	21,178	2,853	5,670	1,007	239	386	2,660	2,237	64	2,364	200	23,840	8,313	1,632	361	387	.268	.339	.393	.732
3	Browns	.383	235	379	625	21,579	3,010	5,814	1,074	202	392	2,853	2,478	69	2,321	200	24,516	8,468	1,668	390	344	.269	.347	.392	.739
4	Braves	.438	267	342	613	21,279	2,348	5,429	848	166	217	2,163	1,663	74	2,227	199	23,348	7,260	1,231	332	340	.255	.311	.341	.653
5	Senators	.448	274	337	615	21,694	2,909	6,040	1,050	298	233	2,688	2,055	61	1,824	332	24,160	8,385	1,581	350	318	.278	.343	.387	.729
6	Giants	.505	306	300	611	21,103	2,738	5,643	870	155	427	2,562	1,920	125	2,023	138	23,526	8,104	1,452	378	399	.267	.332	.384	.716
7	White Sox	.507	309	301	615	21,268	2,837	5,765	942	221	251	2,574	2,100	69	2,036	312	23,853	7,902	1,414	416	360	.271	.339	.372	.710
8	Pirates	.512	313	298	617	21,454	2,872	5,892	1,035	259	260	2,650	2,060	88	1,839	219	23,997	8,225	1,554	395	363	.275	.341	.383	.724
9	Cubs	.518	318	296	619	21,245	2,784	5,606	1,016	205	341	2,581	2,086	106	2,263	212	23,833	8,055	1,562	396	332	.264	.333	.379	.712
10	Tigers	.536	330	286	620	21,384	3,285	5,882	1,055	239	476	3,074	2,578	85	2,309	273	24,426	8,843	1,770	379	358	.275	.355	.414	.769
11	Indians	.549	337	277	617	21,316	3,031	5,768	1,127	313	402	2,808	2,137	64	2,378	271	23,877	8,727	1,842	360	315	.271	.339	.409	.748
12	Dodgers	.560	341	268	621	21,447	2,909	5,657	1,032	275	333	2,700	2,297	93	2,359	217	24,207	8,238	1,640	370	345	.264	.338	.384	.722
13	Cardinals	.564	344	266	622	21,931	2,985	6,139	1,140	253	378	2,785	1,907	92	2,211	243	24,394	8,919	1,771	464	321	.280	.340	.407	.747
14	Red Sox	.564	343	265	611	21,377	3,529	6,192	1,190	248	491	3,306	2,515	60	2,127	219	24,410	9,351	1,929	458	402	.290	.366	.437	.803
15	Reds	.601	367	244	616	21,359	2,813	5,703	997	188	361	2,609	1,793	125	1,988	205	23,787	8,159	1,546	510	340	.267	.327	.382	.709
16	Yankees	.645	394	217	620	21,440	3,580	5,836	1,028	244	646	3,355	2,713	139	2,329	273	24,570	9,290	1,918	278	325	.272	.358	.433	.791