Between the 1930 and 1939 seasons, the St. Louis Browns had the lowest winning percentage by a team, winning 37.8 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	.378	578	951	1,547	53,691	7,274	14,596	2,775	568	750	6,805	5,405	167	5,667	586	60,268	20,757	4,093	1,005	121	.272	.340	.387	.727
2	Phillies	.381	581	943	1,534	53,687	6,992	14,957	2,722	423	832	6,504	4,277	215	5,391	507	59,248	21,021	3,977	1,069	133	.279	.334	.392	.726
3	Reds	.434	664	866	1,538	53,236	6,388	14,234	2,409	624	667	5,987	4,051	279	5,047	429	58,627	19,892	3,700	1,061	110	.267	.322	.374	.696
4	White Sox	.446	678	841	1,530	53,384	7,390	14,614	2,518	594	572	6,860	5,344	224	4,506	687	60,079	20,036	3,684	1,127	108	.274	.342	.375	.718
5	Bees	.458	700	829	1,540	53,218	6,028	13,927	2,217	487	615	5,600	3,809	234	4,958	384	58,350	18,963	3,319	1,089	119	.262	.314	.356	.670
6	Red Sox	.464	705	815	1,528	53,057	7,429	14,561	2,803	586	715	6,871	5,403	166	5,114	627	59,719	20,681	4,104	1,093	146	.274	.343	.390	.733
7	Athletics	.476	723	795	1,530	53,315	7,989	14,893	2,754	578	1,172	7,494	5,586	195	5,781	525	60,076	22,319	4,504	980	121	.279	.350	.419	.768
8	Dodgers	.481	734	793	1,544	53,740	7,070	14,752	2,593	606	712	6,553	4,687	236	5,450	605	59,590	20,693	3,911	927	130	.275	.335	.385	.720
9	Senators	.527	806	722	1,542	54,839	8,140	15,712	2,786	861	548	7,547	5,512	250	4,325	733	61,655	21,864	4,195	1,054	103	.287	.354	.399	.753
10	Pirates	.531	812	718	1,536	54,042	7,254	15,332	2,619	822	567	6,730	4,550	208	4,268	474	59,913	21,296	4,008	1,113	128	.284	.342	.394	.736
11	Tigers	.533	818	716	1,541	54,104	8,399	15,304	2,945	689	947	7,786	5,781	216	5,346	908	61,077	22,468	4,581	976	125	.283	.354	.415	.770
12	Indians	.538	824	708	1,543	54,143	8,246	15,511	3,123	728	888	7,677	5,222	200	4,971	616	60,585	22,754	4,739	1,020	110	.286	.351	.420	.772
13	Cardinals	.566	869	665	1,549	54,739	7,906	15,609	3,085	672	858	7,334	4,232	228	5,273	763	60,227	22,612	4,615	1,028	116	.285	.339	.413	.752
14	Giants	.569	868	657	1,535	54,097	7,530	15,212	2,379	502	1,140	7,029	4,134	272	4,621	388	59,495	22,015	4,021	992	153	.281	.335	.407	.742
15	Cubs	.579	889	646	1,544	53,966	7,747	15,240	2,796	597	913	7,237	4,868	296	5,353	593	60,356	21,969	4,306	1,226	124	.282	.345	.407	.752
16	Yankees	.636	970	554	1,541	54,172	9,695	15,596	2,715	750	1,546	9,070	7,025	281	5,587	822	62,323	24,449	5,011	845	99	.288	.373	.451	.824