Chris Sale has the highest career K/9, with 11.11 per nine innings.

Interpreted as:

most k per 9 with a minimum of 1500 IP by a player by a closer in history

	NAME	K/9	IP	G	W	L	W%	GS	ERA	SO	CG	SHO	SV	H	ER	R	HR	BB	HBP	GF	IBB	TBF	WP	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	ERA-	FIP	FIP-	H/9	PRAA
1	Chris Sale C. Sale	11.11	2047.2	387	143	87	.622	307	3.02	2,528	16	3	12	1,668	686	739	209	481	126	25	15	8,249	47	2.11	5.26	0.92	30.6	5.8	1.05	.297	3.25	71	2.87	69	7.33	296.6
2	Max Scherzer M. Scherzer	10.65	2881.0	467	215	112	.657	458	3.16	3,408	12	5	0	2,349	1,012	1,085	337	756	112	2	20	11,640	78	2.36	4.51	1.05	29.3	6.5	1.08	.286	3.39	76	3.18	77	7.34	307.8
3	Randy Johnson R. Johnson	10.61	4135.1	618	303	166	.646	603	3.29	4,875	100	37	2	3,346	1,513	1,703	411	1,497	190	7	37	17,067	109	3.26	3.26	0.89	28.6	8.8	1.17	.291	3.71	75	3.18	73	7.28	554.3
4	Yu Darvish Y. Darvish	10.59	1706.0	282	110	88	.556	282	3.58	2,007	2	1	0	1,394	678	712	217	544	77	0	8	7,009	79	2.87	3.69	1.14	28.6	7.8	1.14	.283	3.76	85	3.53	84	7.35	125.8
5	Gerrit Cole G. Cole	10.37	1954.0	317	153	80	.657	317	3.18	2,251	8	5	0	1,627	690	740	217	500	61	0	8	7,861	58	2.30	4.50	1.00	28.6	6.4	1.09	.292	3.41	79	3.16	77	7.49	213.5
6	Pedro Martinez P. Martinez	10.04	2827.1	476	219	100	.687	409	2.93	3,154	46	17	3	2,221	919	1,006	239	760	141	23	30	11,394	62	2.42	4.15	0.76	27.7	6.7	1.05	.279	3.20	66	2.91	68	7.07	454.6
7	Aaron Nola A. Nola	9.86	1671.0	277	105	86	.550	277	3.78	1,831	6	4	0	1,482	701	739	210	437	55	0	16	6,855	18	2.35	4.19	1.13	26.7	6.4	1.15	.294	3.98	90	3.49	81	7.98	145.7
8	Clayton Kershaw C. Kershaw	9.71	2770.1	438	214	94	.695	435	2.51	2,988	25	15	0	2,117	772	847	229	688	44	1	28	10,931	104	2.24	4.34	0.74	27.3	6.3	1.01	.270	2.75	64	2.83	70	6.88	368.1
9	Nolan Ryan N. Ryan	9.55	5386.0	807	324	292	.526	773	3.19	5,714	222	61	3	3,923	1,911	2,178	321	2,795	158	13	78	22,575	277	4.67	2.04	0.54	25.3	12.4	1.25	.265	3.64	90	2.96	83	6.56	370.2
10	Corey Kluber C. Kluber	9.46	1641.2	271	116	77	.601	260	3.44	1,725	18	8	1	1,486	627	684	177	368	65	4	9	6,688	31	2.02	4.69	0.97	25.8	5.5	1.13	.301	3.75	83	3.22	78	8.15	161.7
11	Zack Wheeler Z. Wheeler	9.37	1666.2	273	110	72	.604	273	3.30	1,735	4	3	0	1,427	612	663	157	476	70	0	14	6,839	40	2.57	3.64	0.85	25.4	7.0	1.14	.289	3.58	83	3.28	80	7.71	157.3
12	Tim Lincecum T. Lincecum	9.29	1682.0	278	110	89	.553	270	3.74	1,736	10	7	1	1,506	699	746	147	669	44	3	33	7,120	107	3.58	2.59	0.79	24.4	9.4	1.29	.300	3.99	99	3.44	90	8.06	81.5
13	Sandy Koufax S. Koufax	9.28	2324.1	397	165	87	.655	314	2.76	2,396	137	40	9	1,754	713	806	204	817	18	44	48	9,497	87	3.16	2.93	0.79	25.2	8.6	1.11	.256	3.12	75	2.69	75	6.79	226.6
14	Kevin Gausman K. Gausman	9.22	1804.0	344	107	108	.498	305	3.88	1,849	3	1	0	1,753	777	832	224	509	37	11	10	7,559	63	2.54	3.63	1.12	24.5	6.7	1.25	.310	4.15	94	3.62	86	8.75	118.5
15	Carlos Carrasco C. Carrasco	9.07	1673.2	332	112	105	.516	283	4.18	1,687	11	4	2	1,651	777	817	218	461	56	23	21	7,003	60	2.48	3.66	1.17	24.1	6.6	1.26	.313	4.39	101	3.74	90	8.88	77.2
16	Lance Lynn L. Lynn	9.04	2006.1	364	142	99	.589	340	3.74	2,015	4	2	1	1,856	834	916	231	704	89	4	21	8,520	61	3.16	2.86	1.04	23.7	8.3	1.28	.296	4.11	91	3.82	93	8.33	67.8
17	Francisco Liriano F. Liriano	9.01	1813.2	419	112	114	.496	300	4.15	1,815	3	1	1	1,649	837	911	184	816	62	19	15	7,781	100	4.05	2.22	0.91	23.3	10.5	1.36	.299	4.52	101	3.88	95	8.18	39.3
18	Justin Verlander J. Verlander	8.98	3472.1	537	262	151	.634	537	3.32	3,463	26	9	0	2,950	1,280	1,385	364	974	116	0	27	14,192	97	2.52	3.56	0.94	24.4	6.9	1.13	.279	3.59	79	3.43	81	7.65	303.2
19	Sonny Gray S. Gray	8.96	1817.0	321	117	96	.549	312	3.52	1,809	6	4	0	1,569	711	779	177	598	56	2	5	7,525	105	2.96	3.03	0.88	24.0	7.9	1.19	.285	3.86	85	3.51	85	7.77	129.1
20	Sam McDowell S. McDowell	8.86	2492.1	425	141	134	.513	346	3.17	2,453	103	23	14	1,948	879	999	164	1,312	59	39	74	10,587	140	4.74	1.87	0.59	23.2	12.4	1.31	.270	3.61	90	3.06	84	7.03	160.4
21	Johan Santana J. Santana	8.83	2025.2	360	139	78	.641	284	3.20	1,988	15	10	1	1,726	721	773	220	567	36	23	13	8,262	68	2.52	3.51	0.98	24.1	6.9	1.13	.276	3.43	74	3.43	81	7.67	187.6
22	Hideo Nomo H. Nomo	8.73	1976.1	323	123	109	.530	318	4.24	1,918	16	9	0	1,768	932	993	251	908	38	2	31	8,462	109	4.13	2.11	1.14	22.7	10.7	1.35	.284	4.52	102	4.22	98	8.05	14.5
23	David Price D. Price	8.72	2143.2	400	157	82	.657	322	3.32	2,076	17	3	3	1,930	790	865	221	562	63	19	16	8,807	40	2.36	3.69	0.93	23.6	6.4	1.16	.290	3.63	81	3.38	83	8.10	165.9
24	Charlie Morton C. Morton	8.71	2192.2	400	142	130	.522	393	4.06	2,121	3	2	0	2,066	990	1,089	213	819	191	1	25	9,409	70	3.36	2.59	0.87	22.5	8.7	1.32	.306	4.47	101	3.84	96	8.48	46.7
25	Gio Gonzalez G. Gonzalez	8.66	1933.0	344	131	101	.565	328	3.70	1,860	4	2	0	1,744	795	857	171	815	50	4	21	8,242	59	3.79	2.28	0.80	22.6	9.9	1.32	.294	3.99	91	3.67	91	8.12	77.3