Between the 1969 and 1978 seasons, the Toronto Blue Jays had the lowest winning percentage by a team, winning 35.1 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	Blue Jays	.351	113	209	322	10,849	1,195	2,725	447	80	198	1,104	947	46	1,464	93	107	12,071	3,926	725	158	71	57	280	.251	.312	.362	.674
2	Mariners	.373	120	202	322	10,818	1,238	2,725	447	70	230	1,160	948	57	1,471	233	114	12,067	4,002	747	149	95	47	226	.252	.313	.370	.683
3	Padres	.404	651	959	1,610	54,062	5,617	12,953	2,018	350	1,017	5,208	4,865	276	9,490	888	484	60,455	18,722	3,385	934	318	547	1,114	.240	.304	.346	.650
4	Expos	.437	705	907	1,613	54,184	6,164	13,300	2,160	315	1,102	5,700	5,438	380	8,704	799	517	61,289	19,396	3,577	911	376	613	1,209	.245	.317	.358	.675
5	Brewers	.439	707	905	1,614	53,973	6,322	13,331	2,097	341	1,240	5,920	5,323	303	9,176	927	628	60,780	19,830	3,678	789	392	384	1,163	.247	.316	.367	.683
6	Indians	.448	718	885	1,603	54,240	6,197	13,685	1,996	287	1,235	5,787	4,851	271	7,678	687	607	60,466	19,960	3,518	686	418	394	1,330	.252	.315	.368	.683
7	White Sox	.465	747	860	1,610	54,529	6,496	13,987	2,103	343	1,192	6,045	5,208	375	8,217	783	517	61,186	20,352	3,638	614	460	433	1,267	.257	.323	.373	.696
8	Rangers	.467	750	857	1,608	54,205	6,416	13,528	2,005	301	1,118	5,968	5,755	326	8,627	1,061	616	61,415	19,489	3,424	698	431	483	1,304	.250	.323	.360	.682
9	Braves	.467	752	858	1,613	54,707	6,639	13,924	1,967	281	1,375	6,202	5,371	272	7,880	678	464	61,543	20,578	3,623	784	409	606	1,302	.255	.322	.376	.698
10	Angels	.474	764	848	1,614	54,058	5,915	13,285	1,982	305	921	5,484	4,988	366	8,330	1,021	609	60,611	18,640	3,208	770	429	479	1,234	.246	.311	.345	.656
11	Astros	.488	785	825	1,611	54,669	6,621	13,855	2,266	462	1,016	6,128	5,241	306	8,567	1,275	569	61,371	20,093	3,744	730	425	632	1,192	.253	.320	.368	.687
12	Phillies	.490	791	822	1,613	54,804	6,678	13,910	2,367	418	1,242	6,216	5,276	317	9,383	956	560	61,526	20,839	4,027	654	475	664	1,104	.254	.320	.380	.701
13	Tigers	.493	794	816	1,610	54,507	6,495	13,717	2,025	360	1,440	6,076	5,050	323	7,961	531	390	60,858	20,782	3,825	556	422	427	1,334	.252	.317	.381	.698
14	Cubs	.494	797	815	1,614	54,768	6,810	14,045	2,213	371	1,192	6,314	5,690	275	8,249	640	490	61,989	20,576	3,776	796	460	673	1,261	.256	.327	.376	.703
15	Mets	.496	800	813	1,613	54,252	6,078	13,234	2,023	334	990	5,615	5,624	292	8,957	680	468	61,395	18,895	3,347	829	398	584	1,345	.244	.316	.348	.664
16	Cardinals	.497	801	812	1,615	55,314	6,594	14,535	2,338	475	845	6,112	4,979	272	7,980	1,174	563	61,696	20,358	3,658	686	445	685	1,327	.263	.324	.368	.692
17	Giants	.504	813	799	1,612	54,537	6,825	13,721	2,232	389	1,265	6,293	5,956	339	9,056	961	458	62,019	20,526	3,886	778	409	684	1,207	.252	.327	.376	.703
18	Twins	.515	827	779	1,607	55,314	7,136	14,775	2,254	402	1,163	6,656	5,488	382	8,205	883	542	62,357	21,322	3,819	724	449	551	1,344	.267	.335	.385	.720
19	Royals	.518	835	776	1,612	54,616	6,790	14,119	2,423	472	983	6,347	5,349	316	7,509	1,451	710	61,370	20,435	3,878	585	504	456	1,191	.259	.325	.374	.700
20	Athletics	.542	872	738	1,610	53,969	6,741	13,398	2,033	305	1,373	6,236	5,519	413	9,003	1,534	769	61,074	20,160	3,711	758	415	491	1,111	.248	.320	.374	.694
21	Yankees	.549	883	725	1,610	54,555	6,736	14,170	2,203	359	1,176	6,334	5,223	283	7,126	926	533	61,076	20,619	3,738	537	478	461	1,215	.260	.325	.378	.703
22	Red Sox	.553	891	720	1,611	54,706	7,461	14,393	2,501	387	1,594	7,024	5,651	334	8,430	727	488	61,788	22,450	4,482	590	507	482	1,321	.263	.333	.410	.743
23	Pirates	.562	906	705	1,611	55,898	7,226	15,047	2,445	534	1,277	6,719	4,572	352	8,666	984	473	61,886	22,391	4,256	604	460	731	1,191	.269	.326	.401	.726
24	Dodgers	.569	916	695	1,612	55,043	6,866	14,367	2,150	379	1,175	6,402	5,383	249	8,103	1,167	533	62,039	20,800	3,704	885	479	718	1,180	.261	.327	.378	.705
25	Reds	.591	952	659	1,613	55,068	7,592	14,519	2,485	402	1,478	7,068	6,005	314	9,362	1,372	523	62,584	22,242	4,365	717	480	696	1,171	.264	.337	.404	.741