The Seattle Mariners have a 21-21 record on June 30 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	Mariners	6/30/1978	0-1	SEA	vs	MIL	L 3-13	.000	36	3	9	1	0	1	3	4	0	7	0	0	40	13	2	0	0	0	0	.250	.325	.361	.686
2	Mariners	6/30/1979	0-1	SEA	@	MIL	L 1-8	.000	30	1	4	1	0	1	1	4	0	4	0	0	34	8	2	0	0	0	1	.133	.235	.267	.502
3	Mariners	6/30/1980	0-1	SEA	vs	TEX	L 5-11	.000	39	5	14	2	0	1	5	2	0	3	1	0	42	19	3	0	1	1	1	.359	.381	.487	.868
4	Mariners	6/30/1982	1-0	SEA	@	TOR	W 10-4	1.000	43	10	16	2	1	3	10	2	0	3	0	0	45	29	6	0	0	1	0	.372	.400	.674	1.074
5	Mariners	6/30/1984	1-0	SEA	@	BOS	W 2-1	1.000	30	2	4	3	0	1	2	1	0	7	0	0	32	10	4	0	1	0	0	.133	.156	.333	.490
6	Mariners	6/30/1985	0-1	SEA	vs	CLE	L 3-7	.000	34	3	9	3	0	1	3	1	0	5	1	0	36	15	4	0	1	0	1	.265	.278	.441	.719
7	Mariners	6/30/1986	1-0	SEA	vs	KCR	W 3-2	1.000	29	3	6	2	0	0	3	3	0	4	0	1	32	8	2	0	0	0	0	.207	.281	.276	.557
8	Mariners	6/30/1987	1-0	SEA	@	TEX	W 5-2	1.000	33	5	8	3	0	1	5	2	0	5	1	2	35	14	4	0	0	0	0	.242	.286	.424	.710
9	Mariners	6/30/1989	1-0	SEA	@	TEX	W 4-3	1.000	33	4	8	0	0	1	3	3	0	11	1	0	36	11	1	0	0	0	1	.242	.306	.333	.639
10	Mariners	6/30/1990	1-0	SEA	vs	MIL	W 6-2	1.000	32	6	10	3	0	2	6	2	2	4	2	0	36	19	5	0	0	0	2	.313	.389	.594	.983
11	Mariners	6/30/1991	0-1	SEA	@	TOR	L 1-6	.000	30	1	4	2	0	0	1	1	1	2	0	0	32	6	2	0	0	0	1	.133	.188	.200	.388
12	Mariners	6/30/1992	0-1	SEA	vs	OAK	L 2-4	.000	30	2	6	0	0	0	2	5	0	4	0	0	35	6	0	0	0	0	3	.200	.314	.200	.514
13	Mariners	6/30/1993	1-0	SEA	@	MIN	W 5-3	1.000	32	5	12	3	1	0	5	6	0	2	1	0	41	17	4	1	2	2	3	.375	.450	.531	.981
14	Mariners	6/30/1995	0-1	SEA	vs	TEX	L 2-10	.000	32	2	6	1	0	2	2	4	1	4	2	1	37	13	3	0	0	0	0	.188	.297	.406	.704
15	Mariners	6/30/1996	1-0	SEA	vs	TEX	W 4-3	1.000	34	4	12	3	0	0	4	4	0	7	0	0	39	15	3	0	1	0	0	.353	.410	.441	.851
16	Mariners	6/30/1997	0-1	SEA	vs	SFG	L 6-8	.000	40	6	13	1	0	3	6	3	1	8	0	0	44	23	4	0	0	0	1	.325	.386	.575	.961
17	Mariners	6/30/1998	0-1	SEA	vs	COL	L 4-6	.000	34	4	8	1	0	2	4	4	1	6	1	0	39	15	3	0	0	0	2	.235	.333	.441	.775
18	Mariners	6/30/1999	0-1	SEA	@	OAK	L 5-14	.000	40	5	12	3	0	0	3	5	0	5	1	0	45	15	3	0	0	0	1	.300	.378	.375	.753
19	Mariners	6/30/2000	0-1	SEA	@	TEX	L 3-13	.000	32	3	8	4	0	1	3	2	1	7	0	0	35	15	5	0	0	0	4	.250	.314	.469	.783
20	Mariners	6/30/2001	1-0	SEA	@	ANA	W 5-3	1.000	35	5	10	2	2	1	4	2	1	6	0	2	38	19	5	0	0	0	1	.286	.342	.543	.885
21	Mariners	6/30/2002	0-1	SEA	vs	COL	L 3-4	.000	33	3	6	3	0	2	3	5	0	3	2	0	38	15	5	0	0	1	0	.182	.289	.455	.744
22	Mariners	6/30/2003	1-0	SEA	@	OAK	W 3-1	1.000	32	3	7	0	0	1	3	0	0	2	0	0	34	10	1	2	0	0	0	.219	.219	.313	.531
23	Mariners	6/30/2004	0-1	SEA	vs	TEX	L 6-9	.000	35	6	9	1	0	1	6	3	0	6	0	0	38	13	2	0	0	0	1	.257	.316	.371	.687
24	Mariners	6/30/2005	0-1	SEA	@	OAK	L 2-6	.000	33	2	8	0	0	2	2	2	0	5	0	1	35	14	2	0	0	0	1	.242	.286	.424	.710
25	Mariners	6/30/2006	0-1	SEA	vs	COL	L 0-2	.000	26	0	2	0	0	0	0	1	0	1	0	0	27	2	0	0	0	0	3	.077	.111	.077	.188
	Total		21-21					.500	1,440	189	382	65	8	57	181	117	15	253	29	9	1,592	634	130	7	13	10	36	.265	.324	.440	.765