Between the 2006 and 2015 seasons, the Houston Astros had the worst winning percentage by a team, winning 43.8 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	IBB	GIDP	AVG	OBP	SLG	OPS
1	Astros	.438	709	910	1,619	54,833	6,590	13,764	2,705	253	1,540	6,262	4,715	523	12,083	1,047	426	61,047	21,595	4,498	591	385	319	1,222	.251	.314	.394	.708
2	Mariners	.462	749	871	1,620	55,416	6,463	13,944	2,594	239	1,490	6,125	4,394	445	11,462	951	356	61,006	21,486	4,323	374	377	336	1,176	.252	.310	.388	.698
3	Royals	.464	751	869	1,620	55,844	6,945	14,883	2,953	376	1,217	6,586	4,253	533	10,154	1,120	393	61,473	22,239	4,546	393	450	302	1,358	.267	.322	.398	.720
4	Marlins	.464	751	868	1,619	55,126	6,814	14,012	2,785	346	1,525	6,462	4,977	559	12,826	950	358	61,727	22,064	4,656	666	399	433	1,163	.254	.320	.400	.720
5	Pirates	.464	752	867	1,619	55,044	6,647	13,928	2,845	294	1,427	6,360	4,741	638	12,281	847	378	61,459	21,642	4,566	622	414	388	1,220	.253	.317	.393	.711
6	Rockies	.469	760	861	1,621	55,642	7,685	14,913	2,962	440	1,711	7,308	5,215	469	12,202	1,043	419	62,501	23,888	5,113	741	434	444	1,182	.268	.334	.429	.763
7	Orioles	.470	761	858	1,619	55,818	7,243	14,592	2,838	199	1,816	6,927	4,615	506	11,052	804	310	61,645	23,276	4,853	293	413	296	1,330	.261	.321	.417	.738
8	Cubs	.478	774	844	1,618	55,273	6,887	14,073	2,920	302	1,596	6,538	4,922	539	12,251	791	358	61,654	22,385	4,818	556	364	364	1,217	.255	.320	.405	.725
9	Nationals	.478	774	844	1,618	54,879	6,825	13,917	2,768	262	1,547	6,471	5,241	551	12,295	913	356	61,738	21,850	4,577	653	414	385	1,244	.254	.323	.398	.721
10	Padres	.481	779	842	1,621	54,722	6,459	13,411	2,634	328	1,374	6,126	5,164	484	12,445	1,036	338	61,404	20,823	4,336	613	421	399	1,136	.245	.314	.381	.694
11	Diamondbacks	.483	782	838	1,620	55,250	7,123	14,099	2,993	400	1,582	6,802	5,260	470	12,324	937	382	61,972	22,638	4,975	542	450	450	1,167	.255	.323	.410	.733
12	Twins	.488	792	830	1,622	55,588	7,291	14,612	2,842	341	1,355	6,899	5,136	453	10,818	916	357	62,011	22,201	4,538	354	480	358	1,357	.263	.328	.399	.727
13	White Sox	.490	794	827	1,621	55,257	7,130	14,224	2,601	217	1,826	6,841	4,743	622	11,157	959	466	61,391	22,737	4,644	348	421	280	1,313	.257	.321	.411	.732
14	Indians	.491	795	824	1,619	55,334	7,359	14,327	3,032	249	1,578	7,027	5,481	638	11,999	885	334	62,281	22,591	4,859	357	471	331	1,240	.259	.330	.408	.738
15	Reds	.494	801	819	1,620	55,182	7,036	13,979	2,771	230	1,762	6,712	5,275	576	12,045	1,002	396	62,185	22,496	4,763	736	416	455	1,106	.253	.323	.408	.730
16	Brewers	.499	808	812	1,620	55,058	7,258	14,160	2,894	337	1,812	6,943	4,898	710	12,022	1,004	362	61,704	23,164	5,043	628	410	408	1,191	.257	.324	.421	.744
17	Mets	.504	817	803	1,620	55,295	7,063	14,145	2,880	323	1,451	6,718	5,333	503	11,372	1,211	372	62,242	22,024	4,654	659	452	523	1,180	.256	.324	.398	.723
18	Blue Jays	.506	820	800	1,620	55,467	7,614	14,401	3,048	238	1,934	7,268	5,167	505	10,940	865	303	61,911	23,727	5,220	301	471	273	1,305	.260	.326	.428	.754
19	Athletics	.506	820	799	1,619	55,205	7,128	13,844	2,792	277	1,502	6,758	5,635	473	11,310	964	299	62,048	21,696	4,571	262	473	245	1,263	.251	.323	.393	.716
20	Giants	.511	827	792	1,619	55,218	6,701	14,260	2,828	396	1,271	6,334	4,641	452	10,800	837	343	61,390	21,693	4,495	634	445	487	1,307	.258	.319	.393	.711
21	Rays	.514	834	787	1,621	54,882	7,210	13,897	2,794	325	1,712	6,876	5,620	591	12,296	1,285	474	61,887	22,477	4,831	313	481	294	1,157	.253	.327	.410	.736
22	Braves	.517	837	783	1,620	55,160	7,060	14,173	2,813	238	1,542	6,734	5,470	450	11,954	701	320	62,128	22,088	4,593	672	376	439	1,298	.257	.327	.400	.727
23	Rangers	.522	846	775	1,621	55,908	7,904	15,051	3,009	293	1,811	7,504	4,921	535	11,226	1,083	391	62,267	24,079	5,113	409	494	339	1,247	.269	.332	.431	.762
24	Phillies	.523	848	772	1,620	55,754	7,400	14,281	2,820	349	1,739	7,059	5,242	667	11,647	1,075	252	62,659	23,016	4,908	598	398	521	1,124	.256	.325	.413	.738
25	Tigers	.533	864	756	1,620	56,232	7,779	15,391	2,974	369	1,729	7,463	5,023	471	11,246	699	319	62,536	24,290	5,072	365	445	395	1,374	.274	.336	.432	.768