The Boston Red Sox have a 12-12 record against the Yankees in the postseason all-time.

	TEAM	DATE	REC	TM		OPP	RESULT	W%	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	AVG	OBP	SLG	OPS
1	Red Sox	10/13/1999	0-1	BOS	@	NYY	L 3-4	.000	37	3	8	1	0	0	2	2	0	5	1	1	39	9	1	0	0	0	1	.216	.256	.243	.500
2	Red Sox	10/14/1999	0-1	BOS	@	NYY	L 2-3	.000	36	2	10	2	1	1	2	4	1	11	1	0	42	17	4	1	0	1	0	.278	.366	.472	.838
3	Red Sox	10/16/1999	1-0	BOS	vs	NYY	W 13-1	1.000	45	13	21	6	1	3	12	2	0	6	0	0	47	38	10	0	0	0	2	.467	.489	.844	1.334
4	Red Sox	10/17/1999	0-1	BOS	vs	NYY	L 2-9	.000	33	2	10	3	0	0	2	1	0	6	1	0	34	13	3	0	0	0	3	.303	.324	.394	.717
5	Red Sox	10/18/1999	0-1	BOS	vs	NYY	L 1-6	.000	33	1	5	1	0	1	1	6	0	10	1	0	39	9	2	0	0	0	0	.152	.282	.273	.555
6	Red Sox	10/8/2003	1-0	BOS	@	NYY	W 5-2	1.000	39	5	13	0	0	3	5	2	1	7	0	1	42	22	3	0	0	0	0	.333	.381	.564	.945
7	Red Sox	10/9/2003	0-1	BOS	@	NYY	L 2-6	.000	35	2	10	1	0	1	2	2	0	8	1	1	37	14	2	0	0	0	1	.286	.324	.400	.724
8	Red Sox	10/11/2003	0-1	BOS	vs	NYY	L 3-4	.000	30	3	6	1	0	0	2	3	0	7	0	1	33	7	1	0	0	0	2	.200	.273	.233	.506
9	Red Sox	10/13/2003	1-0	BOS	vs	NYY	W 3-2	1.000	27	3	6	1	0	2	3	2	1	10	0	2	30	13	3	0	0	1	2	.222	.300	.481	.781
10	Red Sox	10/14/2003	0-1	BOS	vs	NYY	L 2-4	.000	33	2	6	0	1	1	2	2	1	6	0	0	36	11	2	0	0	0	1	.182	.250	.333	.583
11	Red Sox	10/15/2003	1-0	BOS	@	NYY	W 9-6	1.000	42	9	16	4	1	2	8	5	0	13	1	0	47	28	7	0	0	1	2	.381	.447	.667	1.113
12	Red Sox	10/16/2003	0-1	BOS	@	NYY	L 5-6	.000	44	5	11	2	0	3	4	1	0	9	0	0	45	22	5	0	0	0	1	.250	.267	.500	.767
13	Red Sox	10/12/2004	0-1	BOS	@	NYY	L 7-10	.000	36	7	10	2	1	1	7	0	0	10	0	0	36	17	4	0	0	0	1	.278	.278	.472	.750
14	Red Sox	10/13/2004	0-1	BOS	@	NYY	L 1-3	.000	31	1	5	2	0	0	1	1	0	6	0	0	32	7	2	0	0	0	1	.161	.188	.226	.413
15	Red Sox	10/16/2004	0-1	BOS	vs	NYY	L 8-19	.000	40	8	15	5	0	2	7	4	0	8	0	0	44	26	7	0	0	0	0	.375	.432	.650	1.082
16	Red Sox	10/17/2004	1-0	BOS	vs	NYY	W 6-4	1.000	40	6	8	0	0	1	6	8	0	10	2	0	49	11	1	1	0	0	1	.200	.333	.275	.608
17	Red Sox	10/18/2004	1-0	BOS	vs	NYY	W 5-4	1.000	50	5	13	2	0	1	5	7	0	12	0	2	58	18	3	0	1	0	2	.260	.345	.360	.705
18	Red Sox	10/19/2004	1-0	BOS	@	NYY	W 4-2	1.000	36	4	11	1	0	1	4	1	1	2	1	0	38	15	2	0	0	0	2	.306	.342	.417	.759
19	Red Sox	10/20/2004	1-0	BOS	@	NYY	W 10-3	1.000	38	10	13	0	0	4	10	7	0	5	1	0	46	25	4	0	1	0	1	.342	.435	.658	1.093
20	Red Sox	10/5/2018	1-0	BOS	vs	NYY	W 5-4	1.000	30	5	8	1	0	1	5	3	0	7	1	0	35	12	2	1	1	1	0	.267	.324	.400	.724
21	Red Sox	10/6/2018	0-1	BOS	vs	NYY	L 2-6	.000	31	2	5	1	0	1	2	3	0	6	1	0	34	9	2	0	0	0	1	.161	.235	.290	.526
22	Red Sox	10/8/2018	1-0	BOS	@	NYY	W 16-1	1.000	44	16	18	3	1	1	15	8	0	4	2	0	53	26	5	0	1	0	0	.409	.491	.591	1.081
23	Red Sox	10/9/2018	1-0	BOS	@	NYY	W 4-3	1.000	35	4	8	2	0	1	4	4	1	12	1	0	41	13	3	0	1	1	0	.229	.317	.371	.689
24	Red Sox	10/5/2021	1-0	BOS	vs	NYY	W 6-2	1.000	28	6	7	2	0	2	6	7	0	9	0	0	35	15	4	0	0	0	2	.250	.400	.536	.936
	Total		12-12					.500	873	124	243	43	6	33	117	85	6	189	15	8	972	397	82	3	5	5	26	.278	.345	.455	.799