which team has the worst record against any other given team all-time

The Cincinnati Reds have the worst record by a team against a team, with a record of 6-21 against the Mariners.

	TEAM	REC	OPP	W%	G	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	Reds	6-21	Mariners	.222	27	6	21	885	103	203	42	2	28	100	83	17	207	12	7	1,001	333	72	9	7	4	18	.229	.305	.376	.682
2	Reds	6-17	Red Sox	.261	23	6	17	759	70	171	29	5	19	62	67	8	194	7	4	843	267	53	3	6	1	20	.225	.293	.352	.645
3	Athletics	7-18	Braves	.280	25	7	18	825	97	177	33	2	28	93	97	8	191	6	4	939	298	63	6	3	5	24	.215	.302	.361	.663
4	Cubs	7-18	Yankees	.280	25	7	18	866	76	181	31	11	18	73	69	7	217	12	8	957	288	60	11	4	6	13	.209	.272	.333	.604
5	Twins	8-20	Braves	.286	28	8	20	971	104	230	44	3	22	101	77	8	231	13	5	1,065	346	69	3	6	6	11	.237	.297	.356	.653
6	Athletics	7-17	Cubs	.292	24	7	17	788	74	176	26	4	22	66	61	5	189	8	7	861	276	52	5	2	0	20	.223	.283	.350	.633
7	Pirates	7-17	Athletics	.292	24	7	17	808	79	182	27	4	17	76	84	10	184	15	3	913	268	48	7	4	5	18	.225	.305	.332	.636
8	White Sox	8-19	Diamondbacks	.296	27	8	19	909	105	215	38	2	40	102	59	3	213	6	3	974	377	80	1	2	4	24	.237	.285	.415	.699
9	Orioles	7-15	Cubs	.318	22	7	15	740	84	177	38	3	19	80	55	11	166	7	2	812	278	60	1	5	2	16	.239	.300	.376	.675
10	Orioles	14-30	Marlins	.318	44	14	30	1,481	172	377	73	4	46	163	128	15	286	13	6	1,641	596	123	8	9	7	40	.255	.318	.402	.721
11	Twins	8-17	Dodgers	.320	25	8	17	850	99	200	43	6	20	93	69	8	213	18	1	938	315	69	6	5	2	16	.235	.297	.371	.668
12	Marlins	16-34	Red Sox	.320	50	16	34	1,704	217	436	77	12	47	202	144	24	372	38	12	1,897	678	136	9	16	6	33	.256	.320	.398	.718
13	Orioles	12-25	White Sox	.324	39	12	25	1,316	177	369	55	18	3	146	94	17	54	41		1,461	469	76	34				.280	.336	.356	.693
14	Cardinals	7-14	Rangers	.333	21	7	14	695	89	162	31	2	19	87	58	9	134	7	5	773	254	52	4	7	2	17	.233	.298	.365	.663
15	Pirates	8-16	Blue Jays	.333	24	8	16	829	88	193	32	7	18	83	62	8	195	12	4	911	293	57	5	7	3	10	.233	.290	.353	.644
16	Mets	8-16	Mariners	.333	24	8	16	779	67	170	24	7	21	65	63	13	193	11	4	864	271	52	3	6	1	15	.218	.286	.348	.634
17	Giants	8-16	Yankees	.333	24	8	16	812	79	177	38	1	17	74	87	8	213	13	2	916	268	56	5	4	5	13	.218	.299	.330	.629
18	Guardians	8-16	Mets	.333	24	8	16	790	109	191	44	1	20	103	73	6	181	14	7	879	297	65	5	5	1	20	.242	.309	.376	.685
19	Rockies	16-32	Angels	.333	48	16	32	1,667	211	437	96	9	50	201	132	20	383	28	13	1,848	701	155	16	13	9	30	.262	.322	.421	.742
20	Cardinals	17-33	Tigers	.340	50	17	33	1,719	211	453	80	5	53	201	162	20	373	16	17	1,936	702	138	14	21	16	33	.264	.330	.408	.739
21	Terrapins	15-29	Rebels	.341	46	15	29	1,529	172	392	57	29	12	146	112	7	146	29		1,698	543	98	50				.256	.310	.355	.665
22	Tip-Tops	15-29	Peppers	.341	44	15	29	1,448	169	381	50	15	5	138	132	23		62		1,640	476	70	37				.263	.334	.329	.663
23	Orioles	13-25	Americans	.342	38	13	25	1,299	184	333	53	37	5	159	96	11	9	51		1,424	475	95	18				.256	.313	.366	.679
24	Padres	10-19	Twins	.345	29	10	19	992	108	239	45	4	29	105	70	9	233	19	4	1,086	379	78	9	6	5	14	.241	.295	.382	.677
25	Mariners	12-22	Nationals	.353	34	12	22	1,138	103	278	38	2	30	100	81	8	257	23	6	1,239	410	70	6	6	7	27	.244	.298	.360	.658