Between the 2003 and 2012 seasons, the Kansas City Royals had the lowest winning percentage by a team, winning 41.9 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	Royals	.419	678	942	1,620	55,784	7,179	14,890	2,951	373	1,309	6,782	4,429	575	10,139	950	414	61,685	22,514	4,633	438	459	297	1,360	.267	.325	.404	.728
2	Pirates	.424	686	932	1,618	55,028	6,747	14,049	2,839	324	1,414	6,452	4,706	637	11,592	773	351	61,466	21,778	4,577	657	438	368	1,217	.255	.319	.396	.715
3	Orioles	.446	722	897	1,620	56,069	7,394	14,950	2,922	218	1,686	7,039	4,786	522	10,064	910	350	62,169	23,366	4,826	348	444	305	1,380	.267	.328	.417	.744
4	Mariners	.457	740	880	1,620	55,654	6,741	14,380	2,691	255	1,373	6,378	4,535	473	10,574	1,057	372	61,466	21,700	4,319	393	411	384	1,195	.258	.317	.390	.707
5	Nationals	.457	740	878	1,618	54,810	6,765	13,918	2,860	279	1,469	6,452	5,230	580	11,460	921	404	61,754	21,743	4,608	733	401	447	1,273	.254	.323	.397	.720
6	Rockies	.469	761	860	1,621	55,496	7,913	14,852	3,039	413	1,730	7,525	5,699	532	11,852	921	398	62,966	23,907	5,182	813	426	465	1,233	.268	.339	.431	.770
7	Diamondbacks	.475	770	850	1,620	55,037	7,131	14,045	3,032	386	1,658	6,850	5,431	486	11,827	853	360	61,982	22,823	5,076	580	448	480	1,153	.255	.325	.415	.740
8	Astros	.476	770	849	1,620	54,983	6,923	14,101	2,804	290	1,538	6,582	4,936	574	10,771	964	384	61,629	22,099	4,632	736	400	394	1,257	.256	.322	.402	.724
9	Indians	.480	778	842	1,620	55,712	7,623	14,630	3,133	259	1,673	7,272	5,457	700	11,534	820	395	62,678	23,300	5,065	360	449	353	1,273	.263	.334	.418	.752
10	Padres	.484	785	836	1,621	55,060	6,786	13,918	2,734	339	1,368	6,443	5,534	513	11,475	972	349	62,190	21,434	4,441	627	456	434	1,203	.253	.324	.389	.714
11	Rays	.485	785	834	1,619	55,032	7,433	14,168	2,822	370	1,702	7,088	5,369	585	11,655	1,487	497	61,797	22,836	4,894	328	483	314	1,099	.257	.327	.415	.742
12	Reds	.487	789	831	1,621	55,309	7,367	14,127	2,847	227	1,907	7,039	5,513	628	12,257	908	353	62,531	23,149	4,981	692	389	444	1,120	.255	.328	.419	.746
13	Tigers	.489	793	828	1,621	55,953	7,678	15,058	2,836	409	1,769	7,336	4,939	493	11,051	725	348	62,276	24,019	5,014	445	446	348	1,300	.269	.331	.429	.761
14	Mets	.490	794	825	1,619	55,115	7,180	14,284	2,877	331	1,503	6,817	5,304	493	10,703	1,275	372	62,107	22,332	4,711	734	461	544	1,200	.259	.327	.405	.732
15	Cubs	.491	794	824	1,618	55,507	7,198	14,555	3,014	299	1,697	6,835	4,874	482	11,184	772	347	61,903	23,258	5,010	651	389	395	1,288	.262	.325	.419	.744
16	Marlins	.493	798	821	1,619	55,154	7,229	14,341	2,949	347	1,621	6,852	5,195	611	11,889	1,044	418	62,093	22,847	4,917	708	425	465	1,156	.260	.328	.414	.742
17	Brewers	.494	800	819	1,619	55,121	7,387	14,229	2,973	307	1,866	7,067	5,274	737	12,038	992	353	62,164	23,414	5,146	610	422	464	1,225	.258	.329	.425	.754
18	Blue Jays	.496	803	816	1,619	55,645	7,676	14,586	3,139	279	1,811	7,325	5,130	622	10,634	754	309	62,135	23,716	5,229	253	485	298	1,315	.262	.329	.426	.755
19	Twins	.517	838	784	1,622	55,832	7,535	15,007	2,861	356	1,400	7,107	5,130	494	9,782	1,007	384	62,353	22,780	4,617	400	497	405	1,448	.269	.333	.408	.741
20	Rangers	.518	839	781	1,620	56,347	8,337	15,293	3,116	309	2,078	7,967	5,022	521	11,027	929	323	62,710	25,261	5,503	336	484	336	1,205	.271	.334	.448	.782
21	Athletics	.521	843	776	1,619	55,391	7,271	14,101	2,924	232	1,544	6,919	5,702	505	10,687	855	280	62,351	22,121	4,700	274	479	275	1,321	.255	.327	.399	.727
22	Giants	.522	845	773	1,618	55,042	6,965	14,288	2,897	368	1,387	6,574	5,017	482	10,073	788	349	61,729	22,082	4,652	737	451	638	1,340	.260	.324	.401	.726
23	Dodgers	.523	846	773	1,619	55,073	7,003	14,346	2,678	317	1,393	6,660	5,258	542	10,521	1,069	436	61,986	21,837	4,388	701	412	525	1,294	.260	.329	.397	.725
24	White Sox	.524	850	771	1,621	55,168	7,647	14,434	2,665	200	2,049	7,349	4,964	663	10,305	993	493	61,659	23,646	4,914	434	430	281	1,310	.262	.328	.429	.756
25	Braves	.544	882	738	1,620	55,557	7,705	14,706	3,008	282	1,735	7,357	5,651	461	11,269	719	309	62,804	23,483	5,025	709	426	486	1,303	.265	.335	.423	.758