Nolan Ryan has allowed the fewest career H/9, with 6.56 per nine innings.

Interpreted as:

worst career h/9 with a minimum of 1500 IP by a player

	NAME	H/9	IP	G	W	L	W%	GS	ERA	SO	CG	SHO	SV	H	ER	R	HR	BB	HBP	GF	IBB	TBF	WP	K/9	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	ERA-	FIP	FIP-	PRAA
1	Nolan Ryan N. Ryan	6.56	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	9.55	4.67	2.04	0.54	25.3	12.4	1.25	.265	3.64	90	2.96	83	370.2
2	Sandy Koufax S. Koufax	6.79	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	9.28	3.16	2.93	0.79	25.2	8.6	1.11	.256	3.12	75	2.69	75	226.6
3	Sid Fernandez S. Fernandez	6.85	1866.2	307	114	96	.543	300	3.36	1,743	25	9	1	1,421	696	749	191	715	41	2	33	7,668	22	8.40	3.45	2.44	0.92	22.7	9.3	1.14	.247	3.61	90	3.51	93	50.9
4	J.R. Richard	6.88	1606.0	238	107	71	.601	221	3.15	1,493	76	19	0	1,227	562	625	73	770	17	3	15	6,674	92	8.37	4.32	1.94	0.41	22.4	11.5	1.24	.267	3.50	92	2.85	82	114.7
5	Jacob deGrom J. deGrom	6.88	1502.1	241	94	62	.603	241	2.55	1,809	4	2	0	1,149	426	463	139	338	24	0	13	5,901	28	10.84	2.02	5.35	0.83	30.7	5.7	0.99	.281	2.77	65	2.67	65	238.4
6	Clayton Kershaw C. Kershaw	6.91	2814.1	446	218	96	.694	443	2.52	3,014	25	15	0	2,162	787	864	233	697	46	1	28	11,112	107	9.64	2.23	4.32	0.75	27.1	6.3	1.02	.271	2.76	64	2.84	70	369.9
7	Andy Messersmith A. Messersmith	6.94	2230.1	344	130	99	.568	295	2.86	1,625	98	27	14	1,719	709	812	174	831	40	30	44	9,120	70	6.56	3.35	1.96	0.70	17.8	9.1	1.14	.240	3.28	83	3.28	92	68.3
8	Hoyt Wilhelm H. Wilhelm	7.01	2254.1	1,070	143	122	.540	52	2.52	1,610	20	5	228	1,757	632	773	150	778	62	651	61	9,164	90	6.43	3.11	2.07	0.60	17.6	8.5	1.12	.245	3.09	68	3.06	82	167.6
9	Sam McDowell S. McDowell	7.03	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	8.86	4.74	1.87	0.59	23.2	12.4	1.31	.270	3.61	90	3.06	84	160.4
10	Pedro Martinez P. Martinez	7.07	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	10.04	2.42	4.15	0.76	27.7	6.7	1.05	.279	3.20	66	2.91	68	454.6
11	Ed Walsh E. Walsh	7.12	2964.1	430	195	126	.607	315	1.82	1,736	250	57	35	2,346	598	873	23	617	52	105		11,413	76	5.27	1.87	2.81	0.07	15.2	5.4	1.00	.259	2.65	69	2.02	79	164.3
12	Bob Turley B. Turley	7.18	1712.2	310	101	85	.543	237	3.64	1,265	78	24	13	1,366	693	753	140	1,068	56	38	21	7,447	39	6.65	5.61	1.18	0.74	17.0	14.3	1.42	.249	3.96	98	4.02	108	-66.7
13	Orval Overall O. Overall	7.22	1535.1	218	108	71	.603	182	2.26	935	133	30	12	1,232	385	520	16	551	45	30		6,145	57	5.48	3.23	1.70	0.09	15.2	9.0	1.16	.264	3.05	81	2.39	85	72.4
14	Jeff Tesreau J. Tesreau	7.24	1679.0	247	119	72	.623	207	2.43	880	123	27	9	1,350	453	591	37	572	38	25		6,805	42	4.72	3.07	1.54	0.20	12.9	8.4	1.14	.249	3.17	89	2.79	99	2.5
15	Ed Reulbach E. Reulbach	7.24	2632.1	399	182	106	.632	300	2.28	1,137	200	40	13	2,117	668	887	33	892	107	80		10,521	49	3.89	3.05	1.27	0.11	10.8	8.5	1.14	.250	3.03	80	2.84	99	9
16	Mario Soto M. Soto	7.26	1730.1	297	100	92	.521	224	3.47	1,449	72	13	4	1,395	667	732	172	657	28	20	50	7,147	37	7.54	3.42	2.21	0.89	20.3	9.2	1.19	.253	3.81	93	3.52	95	32.5
17	Randy Johnson R. Johnson	7.28	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	10.61	3.26	3.26	0.89	28.6	8.8	1.17	.291	3.71	75	3.18	73	554.3
18	Addie Joss A. Joss	7.30	2327.0	286	160	97	.623	260	1.89	920	234	45	5	1,888	488	730	19	364	58	22		8,891	28	3.56	1.41	2.53	0.07	10.3	4.1	0.97	.248	2.82	70	2.25	86	88.8
19	Chris Sale C. Sale	7.33	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	11.11	2.11	5.26	0.92	30.6	5.8	1.05	.297	3.25	71	2.88	69	297.2
20	Max Scherzer M. Scherzer	7.34	2925.0	475	217	114	.656	466	3.18	3,456	12	5	0	2,387	1,032	1,105	345	767	114	2	20	11,818	79	10.63	2.36	4.51	1.06	29.2	6.5	1.08	.286	3.40	76	3.20	77	307.8
21	Yu Darvish Y. Darvish	7.37	1739.2	289	112	91	.552	289	3.62	2,036	2	1	0	1,424	699	733	221	555	79	0	8	7,149	82	10.53	2.87	3.67	1.14	28.5	7.8	1.14	.283	3.79	86	3.54	84	125.7
22	Jose DeLeon J. DeLeon	7.38	1897.1	415	86	119	.420	264	3.76	1,594	21	7	6	1,556	793	877	153	841	62	36	50	7,985	60	7.56	3.99	1.90	0.73	20.0	10.5	1.26	.263	4.16	99	3.60	94	44
23	Jim Maloney J. Maloney	7.39	1849.0	302	134	84	.615	262	3.19	1,605	74	30	4	1,518	655	729	138	810	36	18	39	7,745	124	7.81	3.94	1.98	0.67	20.7	10.5	1.26	.268	3.55	87	3.13	88	84.2
24	Rich Gossage R. Gossage	7.45	1809.1	1,002	124	107	.537	37	3.01	1,502	16	0	310	1,497	605	670	119	732	47	681	90	7,507	63	7.47	3.64	2.05	0.59	20.0	9.8	1.23	.270	3.33	81	3.18	84	125.4
25	Tom Seaver T. Seaver	7.47	4783.0	656	311	205	.603	647	2.86	3,640	231	61	1	3,971	1,521	1,674	380	1,390	76	6	116	19,369	126	6.85	2.62	2.62	0.72	18.8	7.2	1.12	.259	3.15	79	3.03	85	286.1