The Seattle Mariners had the lowest run differential per game by a team in 1977, with -1.43.

	TEAM	DIFF/G	DIFF	G	SEASON	W%	W	L	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	AVG	OBP	SLG	OPS
1	Mariners	-1.43	-231	162	1977	.395	64	98	5,460	624	1,398	218	33	133	589	426	35	769	110	67	6,044	2,081	384	81	42	22	114	.256	.312	.381	.693
2	Blue Jays	-1.35	-217	161	1977	.335	54	107	5,419	605	1,367	230	41	100	553	499	23	819	65	55	6,056	1,979	371	81	34	34	156	.252	.316	.365	.681
3	Braves	-1.34	-217	162	1977	.377	61	101	5,534	678	1,404	218	20	139	638	537	17	876	82	53	6,205	2,079	377	83	34	50	135	.254	.320	.376	.696
4	Athletics	-0.89	-144	161	1977	.391	63	98	5,358	605	1,284	176	37	117	548	516	36	910	176	89	6,020	1,885	330	64	46	37	111	.240	.308	.352	.660
5	Padres	-0.88	-142	162	1977	.426	69	93	5,602	692	1,397	245	49	120	652	602	29	1,057	133	57	6,353	2,100	414	90	30	64	102	.249	.324	.375	.699
6	Brewers	-0.78	-126	162	1977	.414	67	95	5,517	639	1,425	255	46	125	598	443	22	862	85	67	6,087	2,147	426	60	45	23	120	.258	.314	.389	.703
7	Mets	-0.47	-76	162	1977	.395	64	98	5,410	587	1,319	227	30	88	525	529	30	887	98	81	6,069	1,870	345	63	37	45	136	.244	.313	.346	.658
8	Expos	-0.44	-71	162	1977	.463	75	87	5,675	665	1,474	294	50	138	622	478	21	877	88	50	6,282	2,282	482	69	39	66	125	.260	.318	.402	.720
9	Indians	-0.39	-63	161	1977	.441	71	90	5,491	676	1,476	221	46	100	631	531	34	688	87	87	6,204	2,089	367	94	54	31	153	.269	.334	.380	.714
10	Cubs	-0.29	-47	162	1977	.500	81	81	5,604	692	1,489	271	37	111	649	534	27	796	64	45	6,286	2,167	419	69	52	59	142	.266	.330	.387	.716
11	Giants	-0.23	-38	162	1977	.463	75	87	5,497	673	1,392	227	41	134	624	568	21	842	90	59	6,215	2,103	402	78	51	61	118	.253	.323	.383	.705
12	Tigers	-0.23	-37	162	1977	.457	74	88	5,604	714	1,480	228	45	166	676	452	20	764	60	46	6,177	2,296	439	45	56	20	132	.264	.318	.410	.728
13	Angels	-0.12	-20	162	1977	.457	74	88	5,410	675	1,380	233	40	131	636	542	36	880	159	89	6,113	2,086	404	74	51	42	116	.255	.324	.386	.710
14	Astros	0.19	30	162	1977	.500	81	81	5,530	680	1,405	263	60	114	638	515	40	839	187	72	6,200	2,130	437	76	39	60	98	.254	.320	.385	.705
15	Cardinals	0.3	49	162	1977	.512	83	79	5,527	737	1,490	252	56	96	686	489	25	823	134	112	6,136	2,142	404	66	29	71	111	.270	.330	.388	.718
16	Orioles	0.41	66	161	1977	.602	97	64	5,494	719	1,433	231	25	148	677	560	24	945	90	51	6,173	2,158	404	48	47	50	132	.261	.329	.393	.722
17	Pirates	0.43	69	162	1977	.593	96	66	5,662	734	1,550	278	57	133	678	474	34	878	260	120	6,262	2,341	468	49	43	74	96	.274	.331	.413	.745
18	White Sox	0.45	73	162	1977	.556	90	72	5,633	844	1,568	254	52	192	809	559	34	666	42	44	6,322	2,502	498	33	63	46	120	.278	.344	.444	.788
19	Reds	0.48	77	162	1977	.543	88	74	5,524	802	1,513	269	42	181	750	600	25	911	170	64	6,261	2,409	492	62	50	63	112	.274	.345	.436	.781
20	Twins	0.57	91	161	1977	.522	84	77	5,639	867	1,588	273	60	123	804	563	43	754	105	65	6,382	2,350	456	81	56	53	115	.282	.348	.417	.765
21	Rangers	0.68	110	162	1977	.580	94	68	5,541	767	1,497	265	39	135	704	596	39	904	154	85	6,342	2,245	439	116	50	47	118	.270	.342	.405	.748
22	Red Sox	0.91	147	161	1977	.602	97	64	5,510	859	1,551	258	56	213	828	528	42	905	66	47	6,184	2,560	527	45	59	38	132	.281	.345	.465	.810
23	Royals	1.06	171	162	1977	.630	102	60	5,594	822	1,549	299	77	146	773	522	45	687	170	87	6,268	2,440	522	49	58	50	104	.277	.340	.436	.776
24	Phillies	1.1	179	162	1977	.623	101	61	5,546	847	1,548	266	56	186	795	573	38	806	135	68	6,290	2,484	508	59	74	75	121	.279	.346	.448	.794
25	Yankees	1.11	180	162	1977	.617	100	62	5,605	831	1,576	267	47	184	784	533	28	681	93	57	6,260	2,489	498	46	48	49	117	.281	.344	.444	.788