what is the most strikeout in a game by a pitcher

Tom Cheney has fanned the most batters in a game, with 21 strikeouts versus the Orioles on September 12, 1962.

Interpreted as:

What is the most strikeout in a regular-season game by a pitcher?

	NAME	SO	DATE	TM		OPP	DEC	GS	ERA	CG	SHO	SV	IP	H	ER	R	HR	BB	HBP	GF	IBB	TBF	WP
1	Tom Cheney T. Cheney	21	9/12/1962	WSH	@	BAL	W	1	0.56	1	0	0	16.0	10	1	1	0	4	0	0	0	62	1
2	Max Scherzer M. Scherzer	20	5/11/2016	WSH	vs	DET	W	1	2.00	1	0	0	9.0	6	2	2	2	0	0	0	0	33	0
3	Randy Johnson R. Johnson	20	5/8/2001	ARI	vs	CIN		1	1.00	0	0	0	9.0	3	1	1	0	0	0	0	0	29	0
4	Kerry Wood K. Wood	20	5/6/1998	CHC	vs	HOU	W	1	0.00	1	1	0	9.0	1	0	0	0	0	1	0	0	29	0
5	Roger Clemens R. Clemens	20	9/18/1996	BOS	@	DET	W	1	0.00	1	1	0	9.0	5	0	0	0	0	0	0	0	32	1
6	Roger Clemens R. Clemens	20	4/29/1986	BOS	vs	SEA	W	1	1.00	1	0	0	9.0	3	1	1	1	0	0	0	0	30	0
7	Randy Johnson R. Johnson	19	8/8/1997	SEA	vs	CWS	W	1	0.00	1	1	0	9.0	5	0	0	0	3	0	0	0	35	0
8	Randy Johnson R. Johnson	19	6/24/1997	SEA	vs	OAK	L	1	4.00	1	0	0	9.0	11	4	4	2	0	0	0	0	37	0
9	David Cone D. Cone	19	10/6/1991	NYM	@	PHI	W	1	0.00	1	1	0	9.0	3	0	0	0	1	0	0	0	31	0
10	Nolan Ryan N. Ryan	19	6/8/1977	CAL	vs	TOR		1	0.00	0	0	0	10.0	6	0	1	0	5	0	0	1	41	2
11	Nolan Ryan N. Ryan	19	8/20/1974	CAL	vs	DET	L	1	0.82	1	0	0	11.0	4	1	1	0	5	0	0	0	41	0
12	Nolan Ryan N. Ryan	19	8/12/1974	CAL	vs	BOS	W	1	2.00	1	0	0	9.0	7	2	2	0	2	0	0	0	36	1
13	Nolan Ryan N. Ryan	19	6/14/1974	CAL	vs	BOS		1	2.08	0	0	0	13.0	8	3	3	1	10	0	0	0	58	0
14	Tom Seaver T. Seaver	19	4/22/1970	NYM	vs	SDP	W	1	1.00	1	0	0	9.0	2	1	1	1	2	0	0	0	31	0
15	Steve Carlton S. Carlton	19	9/15/1969	STL	vs	NYM	L	1	4.00	1	0	0	9.0	9	4	4	2	2	0	0	0	38	1
16	Luis Tiant L. Tiant	19	7/3/1968	CLE	vs	MIN	W	1	0.00	1	1	0	10.0	6	0	0	0	0	0	0	0	36	0
17	Corey Kluber C. Kluber	18	5/13/2015	CLE	vs	STL	W	1	0.00	0	0	0	8.0	1	0	0	0	0	1	0	0	26	0
18	Ben Sheets B. Sheets	18	5/16/2004	MIL	vs	ATL	W	1	1.00	1	0	0	9.0	3	1	1	1	1	0	0	0	31	0
19	Roger Clemens R. Clemens	18	8/25/1998	TOR	vs	KCR	W	1	0.00	1	1	0	9.0	3	0	0	0	0	0	0	0	30	0
20	Randy Johnson R. Johnson	18	9/27/1992	SEA	@	TEX		1	2.25	0	0	0	8.0	6	2	2	0	4	0	0	0	34	0
21	Ramon Martinez R. Martinez	18	6/4/1990	LAD	vs	ATL	W	1	0.00	1	1	0	9.0	3	0	0	0	1	0	0	0	31	0
22	Bill Gullickson B. Gullickson	18	9/10/1980	MON	vs	CHC	W	1	2.00	1	0	0	9.0	4	2	2	0	2	0	0	0	33	1
23	Ron Guidry R. Guidry	18	6/17/1978	NYY	vs	CAL	W	1	0.00	1	1	0	9.0	4	0	0	0	2	0	0	0	33	0
24	Nolan Ryan N. Ryan	18	9/10/1976	CAL	@	CWS	W	1	2.00	1	0	0	9.0	3	2	2	0	9	0	0	0	41	0
25	Don Wilson D. Wilson	18	7/14/1968	HOU	@	CIN	W	1	1.00	1	0	0	9.0	5	1	1	0	2	0	0	0	33	1