Between the 1900 and 1909 seasons, Rube Waddell had the highest K/9, with 7.15 per nine innings.

Interpreted as:

highest k/9 with a minimum of 0.5 IP per team game by a player 1900s

	NAME	K/9	G	W	L	W%	GS	ERA	SO	CG	SHO	SV	IP	H	ER	R	HR	BB	HBP	GF	TBF	WP	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	ERA-	FIP	FIP-	H/9	PRAA
1	Rube Waddell R. Waddell	7.15	385	183	139	.568	328	2.11	2,251	251	49	3	2835.1	2,343	666	1,000	32	772	105	46	11,197	72	2.45	2.92	0.10	20.1	6.9	1.10	.288	3.17	74	1.98	70	7.44	258.7
2	Red Ames R. Ames	6.40	174	72	50	.590	139	2.45	844	91	9	7	1186.2	982	323	475	11	460	24	28	4,806	78	3.49	1.83	0.08	17.6	9.6	1.22	.280	3.60	92	2.24	81	7.45	67.6
3	Harry Krause H. Krause	5.73	36	19	9	.679	23	1.50	149	18	7	0	234.0	171	39	60	2	53	16	9	889	4	2.04	2.81	0.08	16.8	6.0	0.96	.253	2.31	62	1.93	83	6.58	9.9
4	Joe Corbett J. Corbett	5.63	14	5	8	.385	14	4.39	68	12	0	0	108.2	110	53	75	2	51	8	0	517	3	4.22	1.33	0.17	13.2	9.9	1.48	.278	6.21	163	3.04	109	9.11	-3.2
5	Rube Marquard R. Marquard	5.61	30	5	14	.263	23	2.63	111	8	0	1	178.0	161	52	86	2	75	10	4	729	9	3.79	1.48	0.10	15.2	10.3	1.33	.299	4.35	102	2.55	96	8.14	2.1
6	Orval Overall O. Overall	5.53	184	92	60	.605	152	2.13	813	116	25	11	1322.2	1,053	313	443	13	471	43	28	5,295	52	3.20	1.73	0.09	15.4	8.9	1.15	.263	3.01	78	2.35	84	7.17	63.1
7	Harry Suter H. Suter	5.46	18	2	3	.400	7	2.47	53	3	1	1	87.1	72	24	34	2	28	4	11	394	1	2.89	1.89	0.21	13.5	7.1	1.15	.228	3.50	106	2.40	106	7.42	-2.1
8	Christy Mathewson C. Mathewson	5.44	389	236	112	.678	345	1.98	1,799	282	61	16	2974.2	2,435	654	952	37	644	50	39	11,687	90	1.95	2.79	0.11	15.4	5.5	1.04	.262	2.88	71	2.12	73	7.37	248.9
9	Chief Bender C. Bender	5.43	221	102	71	.590	173	2.43	935	147	21	8	1549.0	1,309	419	589	20	362	59	45	6,118	38	2.10	2.58	0.12	15.3	5.9	1.08	.272	3.42	90	2.17	82	7.61	76.5
10	Walter Johnson W. Johnson	5.36	90	32	48	.400	78	1.94	395	61	12	2	663.0	541	143	222	2	157	28	11	2,636	29	2.13	2.52	0.03	15.0	6.0	1.05	.262	3.01	82	1.85	82	7.34	27.1
11	Jimmy Dygert J. Dygert	5.32	156	53	45	.541	97	2.66	524	56	15	2	886.2	717	262	361	9	334	52	43	3,555	30	3.39	1.57	0.09	14.7	9.4	1.19	.269	3.66	104	2.48	102	7.28	-3.3
12	Heinie Berger H. Berger	5.28	77	29	25	.537	60	2.55	313	40	5	1	533.2	447	151	190	3	144	17	13	2,039	22	2.43	2.17	0.05	15.4	7.1	1.11	.284	3.20	105	1.97	86	7.54	19.8
13	Nap Rucker N. Rucker	5.21	117	45	51	.469	100	2.13	531	84	16	2	918.0	752	217	296	10	306	41	16	3,570	20	3.00	1.74	0.10	14.9	8.6	1.15	.277	2.90	90	2.28	92	7.37	17
14	Ed Walsh E. Walsh	4.94	234	110	63	.636	175	1.68	901	138	36	15	1642.1	1,276	307	464	7	312	34	54	6,282	51	1.71	2.89	0.04	14.3	5.0	0.97	.252	2.54	70	1.83	80	6.99	74.3
15	Joe Wood J. Wood	4.86	30	12	8	.600	21	2.21	99	14	5	0	183.1	135	45	63	1	59	7	6	733	5	2.90	1.68	0.05	13.5	8.0	1.06	.236	3.09	89	2.27	95	6.63	3
16	Jim Scott J. Scott	4.85	36	12	12	.500	29	2.30	135	20	4	0	250.1	194	64	86	0	93	16	6	978	6	3.34	1.45	0.00	13.8	9.5	1.15	.264	3.09	99	2.44	108	6.97	-7.4
17	Jim St. Vrain J. St. Vrain	4.83	12	4	6	.400	11	2.08	51	10	1	0	95.0	88	22	36	0	25	5	1	388	3	2.37	2.04	0.00	13.1	6.4	1.19	.287	3.41	78	2.54	91	8.34	2.3
18	Bill Donovan B. Donovan	4.80	295	154	112	.579	273	2.57	1,293	246	31	7	2426.0	2,118	694	938	21	838	71	22	9,906	51	3.11	1.54	0.08	13.1	8.5	1.22	.273	3.48	92	2.68	97	7.86	28.5
19	Tom Hughes T. Hughes	4.79	298	104	135	.435	248	2.99	1,115	195	22	9	2095.1	2,029	697	984	31	637	77	44	8,665	66	2.74	1.75	0.13	12.9	7.4	1.27	.294	4.23	109	2.64	98	8.72	10.4
20	Fred Beebe F. Beebe	4.73	138	42	63	.400	107	2.78	489	74	6	2	931.0	753	288	417	11	379	35	27	3,882	33	3.66	1.29	0.11	12.6	9.8	1.22	.250	4.03	112	2.66	102	7.28	-6.2
21	Jack Coombs J. Coombs	4.61	102	35	35	.500	77	2.45	340	51	13	3	664.1	539	181	249	4	269	25	19	2,693	22	3.64	1.26	0.05	12.6	10.0	1.22	.260	3.37	97	2.60	108	7.30	-13.5
22	Big Jeff Pfeffer B. Jeff Pfeffer	4.55	74	23	34	.404	63	3.05	282	54	5	0	557.1	501	189	252	10	219	27	8	2,251	9	3.54	1.29	0.16	12.5	9.7	1.29	.287	4.07	116	2.89	105	8.09	-7.6
23	Bill Hogg B. Hogg	4.54	116	37	50	.425	89	3.06	368	43	6	1	730.0	677	248	354	13	319	35	21	3,088	33	3.93	1.15	0.16	11.9	10.3	1.36	.282	4.36	111	2.99	112	8.35	-17.4
24	Eddie Plank E. Plank	4.53	334	186	121	.606	314	2.42	1,342	263	36	1	2666.0	2,360	716	955	26	599	140	16	10,645	57	2.02	2.24	0.09	12.6	5.6	1.11	.273	3.22	83	2.42	86	7.97	120.4
25	Bob Groom B. Groom	4.52	44	7	26	.212	31	2.87	131	17	1	0	260.2	218	83	114	2	105	13	9	1,070	10	3.63	1.25	0.07	12.2	9.8	1.24	.264	3.94	121	2.67	116	7.53	-12.3