Sandy Koufax has the highest Game Score in a postseason game, with a Game Score of 88 in Game 7 of the 1965 World Series against the Twins.

Interpreted as:

highest game score by a player in a game 7

	NAME	GSC	DATE	TM		OPP	DEC	GS	ERA	SO	CG	SHO	SV	IP	H	ER	R	HR	BB	HBP	GF	IBB	TBF	WP
1	Sandy Koufax S. Koufax	88	10/14/1965	LAD	@	MIN	W	1	0.00	10	1	1	0	9.0	3	0	0	0	3	0	0	0	33	0
2	Jack Morris J. Morris	84	10/27/1991	MIN	vs	ATL	W	1	0.00	8	1	1	0	10.0	7	0	0	0	2	0	0	1	38	0
3	Ralph Terry R. Terry	83	10/16/1962	NYY	@	SFG	W	1	0.00	4	1	1	0	9.0	4	0	0	0	0	0	0	0	31	0
4	John Smoltz J. Smoltz	82	10/17/1991	ATL	@	PIT	W	1	0.00	8	1	1	0	9.0	6	0	0	0	1	0	0	0	35	0
5	Orel Hershiser O. Hershiser	80	10/12/1988	LAD	vs	NYM	W	1	0.00	5	1	1	0	9.0	5	0	0	0	2	2	0	0	35	1
6	Bob Gibson B. Gibson	80	10/12/1967	STL	@	BOS	W	1	2.00	10	1	0	0	9.0	3	2	2	0	3	0	0	0	32	1
7	Dizzy Dean D. Dean	80	10/9/1934	SLN	@	DET	W	1	0.00	5	1	1	0	9.0	6	0	0	0	0	0	0	0	34	0
8	Bret Saberhagen B. Saberhagen	79	10/27/1985	KCR	vs	STL	W	1	0.00	2	1	1	0	9.0	5	0	0	0	0	0	0	0	32	0
9	Johnny Kucks J. Kucks	79	10/10/1956	NYY	@	BKN	W	1	0.00	1	1	1	0	9.0	3	0	0	0	3	0	0	0	31	0
10	Steve Blass S. Blass	78	10/17/1971	PIT	@	BAL	W	1	1.00	5	1	0	0	9.0	4	1	1	0	2	0	0	0	32	0
11	Stan Coveleski S. Coveleski	78	10/12/1920	CLE	vs	BKN	W	1	0.00	1	1	1	0	9.0	5	0	0	0	0	0	0	0	33	0
12	Danny Cox D. Cox	76	10/14/1987	STL	vs	SFG	W	1	0.00	5	1	1	0	9.0	8	0	0	0	0	0	0	0	32	0
13	Matt Garza M. Garza	75	10/19/2008	TBR	vs	BOS	W	1	1.29	9	0	0	0	7.0	2	1	1	1	3	1	0	0	27	0
14	Tom Glavine T. Glavine	75	10/17/1996	ATL	vs	STL	W	1	0.00	4	0	0	0	7.0	3	0	0	0	0	0	0	0	22	0
15	Lew Burdette L. Burdette	75	10/10/1957	MIL	@	NYY	W	1	0.00	3	1	1	0	9.0	7	0	0	0	1	0	0	1	36	0
16	Babe Adams B. Adams	75	10/16/1909	PIT	@	DET	W	1	0.00	1	1	1	0	9.0	6	0	0	0	1	1	0	0	34	0
17	Mickey Lolich M. Lolich	74	10/10/1968	DET	@	STL	W	1	1.00	4	1	0	0	9.0	5	1	1	1	3	0	0	0	33	0
18	Johnny Podres J. Podres	73	10/4/1955	BKN	@	NYY	W	1	0.00	4	1	1	0	9.0	8	0	0	0	2	0	0	0	35	0
19	Mike Cuellar M. Cuellar	72	10/17/1971	BAL	vs	PIT	L	1	2.25	6	0	0	0	8.0	4	2	2	1	0	0	0	0	28	0
20	Carl Mays C. Mays	71	10/12/1921	NYY	@	NYG	L	1	1.13	7	1	0	0	8.0	6	1	2	0	0	0	0	0	30	0
21	Charlie Morton C. Morton	70	10/17/2020	TBR	vs	HOU	W	1	0.00	6	0	0	0	5.2	2	0	0	0	1	0	0	0	20	0
22	Eddie Cicotte E. Cicotte	70	10/8/1919	CWS	@	CIN	W	1	1.00	4	1	0	0	9.0	7	1	1	0	3	0	0	0	37	0
23	John Smoltz J. Smoltz	69	10/27/1991	ATL	@	MIN		1	0.00	4	0	0	0	7.1	6	0	0	0	1	1	0	0	29	0
24	Frank Viola F. Viola	69	10/25/1987	MIN	vs	STL	W	1	2.25	7	0	0	0	8.0	6	2	2	0	0	0	0	0	29	0
25	Paul Derringer P. Derringer	69	10/8/1940	CIN	vs	DET	W	1	0.00	1	1	0	0	9.0	7	0	1	0	3	0	0	1	36	0