Between the 1997 and 2005 seasons, the Tampa Bay Devil Rays had the worst winning percentage by a team, winning 40.1 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	Devil Rays	.401	518	775	1,293	44,463	5,649	11,675	2,265	274	1,111	5,364	3,788	444	8,366	925	398	49,364	17,821	3,650	325	344	230	994	.263	.324	.401	.725
2	Tigers	.411	599	857	1,456	49,904	6,516	13,038	2,494	371	1,515	6,191	4,227	501	9,553	922	488	55,419	20,819	4,380	357	430	231	1,087	.261	.323	.417	.740
3	Royals	.415	604	851	1,455	50,265	6,919	13,486	2,505	335	1,323	6,523	4,373	524	8,627	993	420	56,065	20,630	4,163	427	476	252	1,158	.268	.330	.410	.741
4	Brewers	.439	639	816	1,456	49,512	6,384	12,685	2,586	233	1,483	6,085	4,910	579	10,535	813	390	55,957	20,186	4,302	585	371	384	1,155	.256	.328	.408	.736
5	Pirates	.442	643	812	1,456	49,472	6,354	12,756	2,517	325	1,322	6,026	4,430	703	9,872	918	414	55,638	19,889	4,164	643	390	338	1,021	.258	.325	.402	.727
6	Nationals	.453	660	798	1,458	49,233	6,181	12,644	2,750	296	1,365	5,865	4,335	490	9,309	767	428	55,145	20,081	4,411	743	344	471	1,115	.257	.321	.408	.729
7	Rockies	.459	669	789	1,458	50,451	7,750	14,210	2,775	369	1,721	7,341	4,844	472	9,267	812	425	56,843	22,886	4,865	670	406	382	1,183	.282	.348	.454	.801
8	Orioles	.468	682	775	1,459	50,250	6,942	13,432	2,641	196	1,608	6,614	4,724	539	8,380	898	400	56,340	21,289	4,445	373	454	290	1,194	.267	.334	.424	.758
9	Reds	.477	696	763	1,461	49,909	6,799	12,940	2,643	235	1,632	6,483	5,039	544	10,664	997	389	56,453	20,949	4,510	604	357	398	1,073	.259	.332	.420	.751
10	Cubs	.480	701	758	1,459	49,830	6,728	12,980	2,506	268	1,706	6,413	4,817	414	10,020	668	340	56,174	21,140	4,480	726	387	438	1,111	.260	.328	.424	.753
11	Marlins	.481	701	756	1,457	49,600	6,456	12,996	2,567	307	1,283	6,100	4,821	535	9,662	1,098	484	55,946	20,026	4,157	587	403	408	1,119	.262	.332	.404	.735
12	Padres	.481	702	756	1,458	49,656	6,587	12,833	2,448	263	1,323	6,259	5,397	397	9,842	951	413	56,323	19,776	4,034	442	431	360	1,142	.258	.333	.398	.732
13	Phillies	.488	711	746	1,457	49,917	6,824	13,103	2,712	310	1,424	6,462	5,395	440	9,901	961	339	56,760	20,707	4,446	585	423	467	1,040	.262	.337	.415	.752
14	Rangers	.490	715	743	1,458	50,920	7,824	14,040	2,797	272	1,993	7,478	4,871	462	9,431	694	327	56,986	23,360	5,062	281	452	310	1,152	.276	.342	.459	.800
15	Twins	.491	714	741	1,456	50,369	6,748	13,521	2,773	326	1,279	6,357	4,534	495	9,194	1,008	474	56,112	20,783	4,378	275	439	323	1,235	.268	.332	.413	.745
16	Blue Jays	.496	722	735	1,458	50,389	7,182	13,401	2,802	275	1,677	6,852	4,692	659	9,728	920	377	56,415	21,784	4,754	241	434	290	1,121	.266	.334	.432	.766
17	Diamondbacks	.503	652	644	1,296	44,443	6,030	11,637	2,262	324	1,405	5,749	4,420	413	8,449	666	301	50,134	18,762	3,991	490	368	404	963	.262	.332	.422	.754
18	Mets	.511	744	713	1,457	49,425	6,523	12,755	2,482	202	1,459	6,193	5,032	478	9,484	858	411	55,951	20,018	4,143	622	394	445	1,153	.258	.330	.405	.735
19	Angels	.521	759	699	1,458	50,395	7,066	13,685	2,584	266	1,471	6,693	4,575	492	8,461	1,049	481	56,313	21,214	4,321	421	430	347	1,099	.272	.336	.421	.756
20	Dodgers	.522	761	697	1,458	49,531	6,493	12,765	2,289	243	1,568	6,188	4,638	482	9,421	955	418	55,668	20,244	4,100	657	360	366	1,081	.258	.325	.409	.734
21	White Sox	.523	762	694	1,458	49,882	7,446	13,506	2,603	255	1,827	7,105	4,738	468	8,485	952	427	55,994	22,100	4,685	445	461	251	1,142	.271	.337	.443	.780
22	Indians	.527	768	689	1,457	50,369	7,660	13,795	2,781	262	1,801	7,284	5,369	503	9,412	894	433	57,092	22,503	4,844	390	461	308	1,219	.274	.347	.447	.794
23	Mariners	.528	770	687	1,457	50,350	7,483	13,736	2,646	252	1,666	7,132	5,356	464	9,384	1,087	406	57,039	21,884	4,564	390	479	400	1,107	.273	.345	.435	.780
24	Athletics	.547	797	660	1,457	50,141	7,425	13,133	2,713	188	1,744	7,062	5,745	549	9,398	552	242	57,120	21,454	4,645	283	402	317	1,196	.262	.342	.428	.770
25	Astros	.549	800	658	1,459	49,742	7,309	13,280	2,709	286	1,630	6,919	5,453	669	9,770	1,011	432	56,954	21,451	4,625	644	446	479	1,172	.267	.345	.431	.776