The Boston Red Sox had a 102-86 record in the postseason before 2021.

	TEAM	REC	SEASON	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	Americans	5-3	1903	.625	8	5	3	281	39	69	4	16	2	34	14	3	29	5	2	304	111	22	6		0	4	.246	.289	.395	.684
2	Red Sox	4-3	1912	.571	8	4	3	273	25	60	14	6	1	21	19	1	36	6	2	299	89	21	6		1	2	.220	.273	.326	.599
3	Red Sox	4-1	1915	.800	5	4	1	159	12	42	2	2	3	11	11	1	25	1	6	177	57	7	6		1	3	.264	.316	.358	.674
4	Red Sox	4-1	1916	.800	5	4	1	164	21	39	7	6	2	18	18	0	25	1	6	192	64	15	10		1	1	.238	.313	.390	.703
5	Red Sox	4-2	1918	.667	6	4	2	172	9	32	2	3	0	6	16	1	21	3	3	197	40	5	8		1	3	.186	.259	.233	.492
6	Red Sox	3-4	1946	.429	7	3	4	233	20	56	7	1	4	18	22	1	28	2	1	259	77	12	3		6	5	.240	.309	.330	.639
7	Red Sox	3-4	1967	.429	7	3	4	222	21	48	6	1	8	19	17	2	49	1	2	247	80	15	4	2	4	3	.216	.276	.360	.636
8	Red Sox	6-4	1975	.600	10	6	4	337	48	91	15	2	8	44	33	1	52	3	2	384	134	25	9	4	6	7	.270	.333	.398	.731
9	Red Sox	7-7	1986	.500	14	7	7	502	68	138	22	4	11	61	47	6	84	1	0	566	201	37	7	4	5	11	.275	.342	.400	.742
10	Red Sox	0-4	1988	.000	4	0	4	126	11	26	4	0	2	10	18	1	23	0	0	149	36	6	2	2	0	4	.206	.306	.286	.592
11	Red Sox	0-4	1990	.000	4	0	4	126	4	23	5	0	1	4	6	0	16	1	0	135	31	6	1	2	0	3	.183	.216	.246	.462
12	Red Sox	0-3	1995	.000	3	0	3	114	6	21	2	0	3	6	11	0	26	2	1	127	32	5	1	1	2	0	.184	.254	.281	.535
13	Red Sox	1-3	1998	.250	4	1	3	135	20	34	6	0	5	19	14	2	28	1	0	154	55	11	1	2	1	3	.252	.327	.407	.734
14	Red Sox	4-6	1999	.400	10	4	6	360	68	110	30	3	15	66	34	4	73	5	2	402	191	48	1	3	4	9	.306	.369	.531	.900
15	Red Sox	6-6	2003	.500	12	6	6	430	46	106	15	2	20	42	35	5	99	5	5	470	185	37	0	0	7	13	.247	.311	.430	.741
16	Red Sox	11-3	2004	.786	14	11	3	525	90	149	29	3	18	87	72	6	96	7	2	609	238	50	2	4	7	13	.284	.374	.453	.827
17	Red Sox	0-3	2005	.000	3	0	3	104	9	25	9	0	3	8	8	0	14	0	0	112	43	12	0	0	1	1	.240	.295	.413	.708
18	Red Sox	11-3	2007	.786	14	11	3	476	99	149	41	1	18	96	66	4	85	6	1	559	246	60	4	9	8	23	.313	.395	.517	.911
19	Red Sox	6-5	2008	.545	11	6	5	396	46	95	23	1	13	45	50	6	84	6	2	455	159	37	1	2	2	9	.240	.333	.402	.734
20	Red Sox	0-3	2009	.000	3	0	3	95	7	15	2	1	1	7	8	0	16	1	0	103	22	4	0	0	0	1	.158	.223	.232	.455
21	Red Sox	11-5	2013	.688	16	11	5	520	72	118	29	3	10	67	59	8	165	12	2	594	183	42	2	5	8	10	.227	.313	.352	.664
22	Red Sox	0-3	2016	.000	3	0	3	98	7	21	7	0	3	7	8	1	31	0	0	108	37	10	0	1	0	2	.214	.278	.378	.655
23	Red Sox	1-3	2017	.250	4	1	3	137	18	39	7	0	5	18	12	0	33	2	0	150	61	12	0	1	0	3	.285	.340	.445	.785
24	Red Sox	11-3	2018	.786	14	11	3	501	84	121	25	1	17	80	59	6	120	7	3	571	199	43	2	3	7	7	.242	.327	.397	.724
	Total	102-86		.543	189	102	86	6,486	850	1,627	313	56	173	794	657	59	1,258	78	42	7,323	2,571	542	76	45	72	140	.251	.323	.396	.720