Between the 1935 and 1944 seasons, the Philadelphia Phillies had the lowest winning percentage by a team, winning 34.7 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	.347	529	997	1,538	52,683	5,735	13,474	2,143	372	691	5,292	4,409	188	5,551	441	58,246	18,434	3,206	966	753	.256	.315	.350	.665
2	Athletics	.371	567	960	1,536	52,889	6,547	13,879	2,324	540	759	6,100	5,115	174	5,560	538	59,059	19,560	3,623	881	794	.262	.329	.370	.699
3	Browns	.422	646	883	1,549	53,518	7,256	14,286	2,682	506	863	6,820	5,916	165	5,875	455	60,570	20,569	4,051	971	652	.267	.342	.384	.726
4	Braves	.425	647	876	1,533	52,745	5,706	13,268	2,150	379	608	5,305	4,327	194	5,570	429	58,190	18,000	3,137	924	650	.252	.311	.341	.652
5	Senators	.462	706	822	1,538	54,144	7,289	14,869	2,498	702	494	6,706	5,475	232	4,724	918	60,653	20,253	3,694	802	629	.275	.344	.374	.718
6	White Sox	.505	769	754	1,532	52,820	6,929	14,119	2,383	532	533	6,340	5,410	192	4,762	847	59,397	19,165	3,448	975	683	.267	.338	.363	.700
7	Dodgers	.515	788	742	1,549	53,714	7,045	14,364	2,569	553	619	6,483	5,224	214	5,278	585	60,116	19,896	3,741	964	664	.267	.335	.370	.705
8	Giants	.519	791	733	1,538	53,310	6,898	14,294	2,112	415	1,041	6,423	4,702	301	4,899	359	59,318	20,359	3,568	1,005	807	.268	.331	.382	.713
9	Pirates	.528	805	721	1,546	53,777	7,117	14,674	2,457	717	599	6,583	5,174	210	4,979	510	60,052	20,362	3,773	891	703	.273	.339	.379	.718
10	Indians	.528	811	725	1,550	53,916	7,378	14,701	2,851	701	896	6,870	5,257	172	5,624	642	60,282	21,642	4,448	937	667	.273	.339	.401	.741
11	Cubs	.530	815	722	1,547	53,584	7,120	14,434	2,514	520	799	6,584	5,185	254	5,349	586	60,131	20,385	3,833	1,108	664	.269	.337	.380	.717
12	Red Sox	.533	813	712	1,537	53,442	7,906	14,862	2,772	590	975	7,357	5,911	191	5,220	658	60,697	21,739	4,337	1,153	714	.278	.352	.407	.759
13	Reds	.533	817	715	1,543	53,138	6,501	13,829	2,336	505	749	6,030	4,385	280	5,125	540	58,843	19,422	3,590	1,040	666	.260	.320	.366	.685
14	Tigers	.543	834	703	1,548	53,822	7,938	14,823	2,628	567	1,039	7,344	6,031	216	5,460	645	61,025	21,702	4,234	956	789	.275	.351	.403	.754
15	Cardinals	.602	924	610	1,558	54,732	7,604	15,260	2,837	639	876	7,051	4,660	210	5,291	609	60,750	22,003	4,352	1,148	599	.279	.338	.402	.740
16	Yankees	.635	971	558	1,544	53,650	8,586	14,717	2,537	660	1,410	8,039	6,467	310	5,741	684	61,183	22,804	4,607	756	690	.274	.356	.425	.781