50 players are tied for the best on-base percentage in a month, with an on-base percentage of 1.000. The first three are José Tena, Miles Mastrobuoni and Ryne Nelson in March 2025.

Interpreted as:

highest obp by a player in a month ever

	NAME	OBP	MONTH	G	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	AVG	SLG	OPS
1	José Tena J. Tena	1.000	March 2025	1	1	0	1	0	0	0	0	0	0	0	0	0	1	1	0	0	0	0	0	1.000	1.000	2.000
2	Miles Mastrobuoni M. Mastrobuoni	1.000	March 2025	1	1	0	1	0	0	0	0	0	0	0	0	0	1	1	0	0	0	0	0	1.000	1.000	2.000
3	Ryne Nelson R. Nelson	1.000	March 2025	1	1	1	1	0	0	0	1	0	0	0	0	0	1	1	0	0	0	0	0	1.000	1.000	2.000
4	Jacob Hurtubise J. Hurtubise	1.000	March 2025	3	0	1	0	0	0	0	0	1	1	0	0	0	2	0	0	0	0	0	0
5	Duke Ellis D. Ellis	1.000	September 2024	3	1	0	1	0	0	0	0	0	0	0	1	0	1	1	0	0	0	0	0	1.000	1.000	2.000
6	Joey Wiemer J. Wiemer	1.000	August 2024	2	0	0	0	0	0	0	0	1	0	0	0	0	1	0	0	0	0	0	0
7	Alika Williams A. Williams	1.000	July 2024	1	0	2	0	0	0	0	1	0	1	0	0	0	1	0	0	0	0	0	0
8	Jacob Wilson J. Wilson	1.000	July 2024	1	1	1	1	0	0	0	0	0	0	0	0	0	1	1	0	0	0	0	0	1.000	1.000	2.000
9	Ben Gamel B. Gamel	1.000	June 2024	2	0	0	0	0	0	0	0	1	0	0	0	0	1	0	0	0	0	0	0
10	Lenyn Sosa L. Sosa	1.000	May 2024	1	1	0	1	0	0	0	0	0	0	0	0	0	1	1	0	0	0	0	0	1.000	1.000	2.000
11	Ryan McKenna R. McKenna	1.000	April 2024	2	1	0	1	0	0	0	0	0	0	0	0	0	1	1	0	0	0	0	0	1.000	1.000	2.000
12	Travis Jankowski T. Jankowski	1.000	March 2024	2	1	1	1	0	0	1	1	0	0	0	0	0	1	4	1	0	0	0	0	1.000	4.000	5.000
13	Royce Lewis R. Lewis	1.000	March 2024	1	2	1	2	0	0	1	1	0	0	0	0	0	2	5	1	0	0	0	0	1.000	2.500	3.500
14	Victor Caratini V. Caratini	1.000	October 2023	1	1	0	1	1	0	0	0	0	0	0	0	0	1	2	1	0	0	0	0	1.000	2.000	3.000
15	Elias Díaz E. Díaz	1.000	October 2023	1	1	0	1	0	0	0	0	0	0	0	0	0	1	1	0	0	0	0	0	1.000	1.000	2.000
16	Matt Olson M. Olson	1.000	October 2023	1	1	0	1	0	0	0	2	0	0	0	0	0	1	1	0	0	0	0	0	1.000	1.000	2.000
17	David Peralta D. Peralta	1.000	October 2023	1	1	0	1	0	0	0	0	0	0	0	0	0	1	1	0	0	0	0	0	1.000	1.000	2.000
18	Dominic Smith D. Smith	1.000	October 2023	1	0	1	0	0	0	0	0	1	0	0	0	0	1	0	0	0	0	1	0
19	Rowdy Tellez R. Tellez	1.000	October 2023	1	0	0	0	0	0	0	0	1	0	0	0	0	1	0	0	0	0	0	0
20	Juan Soto J. Soto	1.000	October 2023	1	0	0	0	0	0	0	0	1	0	0	0	0	1	0	0	0	0	0	0
21	Brent Rooker B. Rooker	1.000	October 2023	1	3	1	3	1	0	1	1	1	0	0	0	0	4	7	2	0	0	0	0	1.000	2.333	3.333
22	Sean Bouchard S. Bouchard	1.000	October 2023	1	1	1	1	0	0	1	1	0	0	0	0	0	1	4	1	0	0	0	0	1.000	4.000	5.000
23	Will Brennan W. Brennan	1.000	October 2023	1	1	0	1	0	0	0	0	0	0	0	0	0	1	1	0	0	0	0	0	1.000	1.000	2.000
24	Luis García Jr. L. García Jr.	1.000	October 2023	1	0	1	0	0	0	0	0	2	0	0	0	0	2	0	0	0	0	0	0
25	Sal Frelick S. Frelick	1.000	October 2023	1	0	0	0	0	0	0	0	1	0	0	0	0	1	0	0	0	0	0	0