The New York Mets had the most runs by a team in a game in 1971, with 20 runs against the Braves on August 7, 1971.

Interpreted as:

MLB team most runs in a regular-season game 1971

	TEAM	R	DATE	TM		OPP	RESULT	AB	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	AVG	OBP	SLG	OPS
1	Mets	20	8/7/1971	NYM	@	ATL	W 20-6	45	21	1	0	2	18	7	0	4	1	0	55	28	3	1	2	1	3	.467	.519	.622	1.141
2	Astros	18	7/7/1971	HOU	@	SFG	W 18-4	45	17	6	0	0	18	4	1	5	2	0	51	23	6	0	1	0	0	.378	.431	.511	.942
3	White Sox	18	6/20/1971	CWS	@	MIN	W 18-8	40	13	3	0	3	14	7	2	5	0	1	49	25	6	0	0	0	0	.325	.449	.625	1.074
4	Giants	16	9/3/1971	SFG	vs	HOU	W 16-6	42	20	5	1	3	16	7	0	9	0	0	49	36	9	0	0	0	0	.476	.551	.857	1.408
5	Braves	15	8/24/1971	ATL	vs	PIT	W 15-5	41	21	4	1	3	14	2	0	4	1	0	45	36	8	1	1	0	1	.512	.523	.878	1.401
6	Pirates	15	8/23/1971	PIT	@	ATL	W 15-4	43	19	2	1	4	15	4	0	6	0	0	48	35	7	1	0	0	3	.442	.489	.814	1.303
7	Giants	15	7/31/1971	SFG	vs	PIT	W 15-11	39	15	6	0	2	13	7	1	8	0	0	48	27	8	1	0	1	0	.385	.489	.692	1.182
8	Senators	15	7/5/1971	WSH	@	CLE	W 15-6	44	18	6	0	3	15	4	0	7	0	0	50	33	9	1	1	0	0	.409	.449	.750	1.199
9	Orioles	15	6/29/1971	BAL	vs	DET	W 15-6	41	17	4	1	2	14	9	2	8	0	0	52	29	7	0	0	0	0	.415	.538	.707	1.246
10	Cubs	15	6/18/1971	CHC	vs	STL	W 15-5	40	19	4	0	3	15	7	2	3	0	0	51	32	7	1	1	1	0	.475	.560	.800	1.360
11	Cardinals	15	5/21/1971	STL	vs	SDP	W 15-8	39	15	4	0	3	15	6	0	4	1	2	47	28	7	1	1	1	0	.385	.457	.718	1.174
12	Dodgers	14	7/4/1971	LAD	@	SFG	W 14-4	43	16	4	0	2	12	6	0	3	0	0	49	26	6	0	0	2	1	.372	.449	.605	1.054
13	Reds	14	6/29/1971	CIN	@	MON	W 14-0	47	23	1	1	2	13	3	1	5	0	0	52	32	4	0	1	0	2	.489	.519	.681	1.200
14	Pirates	14	6/25/1971	PIT	@	PHI	W 14-4	42	14	4	0	5	14	4	1	4	1	0	48	33	9	1	0	0	0	.333	.404	.786	1.190
15	Cardinals	14	4/7/1971	STL	@	CHC	W 14-3	42	13	5	0	0	13	5	1	3	0	0	48	18	5	0	0	0	2	.310	.396	.429	.824
16	Padres	13	8/29/1971	SDP	@	MON	W 13-3	41	15	0	1	3	13	5	0	10	1	0	47	26	4	1	0	1	1	.366	.435	.634	1.069
17	Pirates	13	8/25/1971	PIT	@	ATL	W 13-6	44	21	1	1	2	12	2	0	6	0	0	49	30	4	2	1	0	1	.477	.489	.682	1.171
18	Cardinals	13	8/22/1971	STL	@	ATL	W 13-4	40	15	3	0	2	12	7	1	5	3	1	48	24	5	0	0	0	2	.375	.479	.600	1.079
19	Yankees	13	7/22/1971	NYY	vs	MIN	W 13-4	39	16	3	1	1	13	4	1	5	0	0	47	24	5	2	1	0	0	.410	.467	.615	1.082
20	Red Sox	13	7/17/1971	BOS	vs	MIL	W 13-11	38	14	3	0	3	11	7	0	6	0	0	46	26	6	0	1	0	0	.368	.457	.684	1.141
21	Athletics	13	6/12/1971	OAK	vs	NYY	W 13-3	44	20	1	0	1	12	4	0	5	0	0	49	24	2	1	0	0	1	.455	.500	.545	1.045
22	White Sox	13	5/22/1971	CWS	@	CAL	W 13-0	35	14	2	0	1	12	5	1	5	1	0	45	19	3	2	2	1	2	.400	.465	.543	1.008
23	Giants	12	9/26/1971	SFG	@	CIN	W 12-5	41	17	6	1	3	12	2	0	7	0	0	44	34	10	1	0	1	2	.415	.442	.829	1.271
24	Dodgers	12	9/19/1971	LAD	vs	ATL	W 12-0	38	19	2	0	1	12	6	0	3	0	0	46	24	3	1	1	1	2	.500	.556	.632	1.187
25	Expos	12	9/14/1971	MON	@	NYM	W 12-1	40	14	4	0	1	12	3	2	3	0	0	46	21	5	0	1	0	1	.350	.413	.525	.938