Mark McGwire has the most career home runs per at-bat with 500+ at-bats, with 0.09.

Interpreted as:

most career home runs per at bat by a player with 500+ at bats

	NAME	HR/AB	AB	HR	G	R	H	2B	3B	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	AVG	OBP	SLG	OPS	WRC	WRAA	WOBA	WRC+	BRAA
1	Mark McGwire M. McGwire	0.09	6,187	583	1,874	1,167	1,626	252	6	1,414	1,317	75	1,596	12	8	7,660	3,639	841	3	78	150	147	.263	.394	.588	.982	1480	564.9	.415	157	558.2
2	Aaron Judge A. Judge	0.09	3,970	353	1,105	830	1,160	197	7	805	774	37	1,337	60	19	4,812	2,430	557	0	31	96	112	.292	.410	.612	1.022	1002	427.2	.423	176	430.8
3	Babe Ruth B. Ruth	0.09	8,399	714	2,503	2,174	2,873	506	136	2,214	2,062	43	1,330	123		10,617	5,793	1,356	113				.342	.474	.690	1.164	2727	1,436.8	.513	197	1,369.6
4	Barry Bonds B. Bonds	0.08	9,847	762	2,986	2,227	2,935	601	77	1,996	2,558	106	1,539	514	141	12,606	5,976	1,440	4	91	688	165	.298	.444	.607	1.051	2663	1,143.3	.435	172	1,142
5	Shohei Ohtani S. Ohtani	0.07	3,587	268	980	677	1,010	183	44	647	513	25	1,066	162	43	4,145	2,085	495	0	20	84	46	.282	.373	.581	.955	772	277.8	.396	155	273.9
6	Kyle Schwarber K. Schwarber	0.07	4,392	327	1,251	772	1,018	171	13	753	736	48	1,479	37	19	5,201	2,196	511	1	24	46	51	.232	.347	.500	.847	808	186.8	.359	127	167.7
7	Jim Thome J. Thome	0.07	8,422	612	2,543	1,583	2,328	451	26	1,699	1,747	69	2,548	19	20	10,313	4,667	1,089	1	74	173	165	.276	.402	.554	.956	1925	653.9	.406	145	589.5
8	Joey Gallo J. Gallo	0.07	2,869	208	939	463	557	107	10	453	497	32	1,292	33	10	3,403	1,308	325	1	4	20	16	.194	.319	.456	.775	455	47.6	.332	106	28.2
9	Giancarlo Stanton G. Stanton	0.07	6,169	441	1,692	927	1,594	309	11	1,137	792	54	2,014	42	15	7,054	3,248	761	0	39	90	155	.258	.346	.527	.872	1124	306.3	.369	136	300.3
10	Ralph Kiner R. Kiner	0.07	5,205	369	1,472	971	1,451	216	39	1,015	1,011	24	749	22	2	6,256	2,852	624	9	7	1	126	.279	.398	.548	.946	1167	442.7	.427	147	364.2
11	Pete Alonso P. Alonso	0.07	3,597	254	968	556	904	172	8	685	408	98	940	18	4	4,135	1,854	434	0	32	46	104	.251	.341	.515	.856	651	154.8	.360	133	166.5
12	Harmon Killebrew H. Killebrew	0.07	8,147	573	2,435	1,283	2,086	290	24	1,584	1,559	48	1,699	19	18	9,831	4,143	887	0	77	160	243	.256	.376	.509	.884	1630	569	.389	142	477.8
13	Yordan Alvarez Y. Alvarez	0.07	2,390	167	658	419	704	152	6	484	334	40	554	9	1	2,789	1,369	325	0	25	40	59	.295	.387	.573	.959	532	198.7	.401	162	204.6
14	Sammy Sosa S. Sosa	0.07	8,813	609	2,354	1,475	2,408	379	45	1,667	929	59	2,306	234	107	9,896	4,704	1,033	17	78	154	202	.273	.344	.534	.878	1559	345.1	.370	124	307.3
15	Cal Raleigh C. Raleigh	0.07	2,018	139	584	284	453	89	2	351	240	15	649	20	4	2,289	963	230	0	16	17	27	.224	.309	.477	.787	310	39.9	.335	122	58.1
16	Mike Trout M. Trout	0.07	5,840	398	1,612	1,175	1,726	320	55	1,006	1,046	105	1,607	214	38	7,051	3,350	773	0	60	130	73	.296	.408	.574	.982	1373	553.8	.412	167	555.4
17	Ted Williams T. Williams	0.07	7,706	521	2,292	1,798	2,654	525	71	1,839	2,021	39	709	24	4	9,791	4,884	1,117	5	20	86	197	.344	.482	.634	1.116	2349	1,219.7	.493	188	1,067
18	Manny Ramirez M. Ramirez	0.07	8,244	555	2,302	1,544	2,574	547	20	1,831	1,329	109	1,813	38	33	9,774	4,826	1,122	2	90	216	243	.312	.411	.585	.996	1931	719.5	.418	153	658.7
19	Patrick Wisdom P. Wisdom	0.07	1,311	88	455	192	274	58	3	207	132	21	540	23	8	1,472	602	149	4	4	2	21	.209	.291	.459	.750	184	9.7	.321	104	7.7
20	Adam Dunn A. Dunn	0.07	6,883	462	2,001	1,097	1,631	334	10	1,168	1,317	86	2,379	63	25	8,328	3,371	806	2	40	122	100	.237	.364	.490	.854	1285	297.9	.367	123	240
21	Ryan Howard R. Howard	0.07	5,707	382	1,572	848	1,475	277	21	1,194	709	59	1,843	12	5	6,530	2,940	680	0	55	154	116	.258	.343	.515	.859	976	212.1	.361	121	175.3
22	Ken Phelps K. Phelps	0.07	1,854	123	761	308	443	64	7	313	390	21	449	10	7	2,287	890	194	1	21	28	25	.239	.374	.480	.854	364	103.3	.376	131	86.6
23	Juan Gonzalez J. Gonzalez	0.07	6,556	434	1,689	1,061	1,936	388	25	1,404	457	62	1,273	26	19	7,155	3,676	847	2	78	74	184	.295	.343	.561	.904	1190	314.6	.383	129	264.9
24	Dave Kingman D. Kingman	0.07	6,677	442	1,941	901	1,575	240	25	1,210	608	53	1,816	85	49	7,429	3,191	707	16	75	72	139	.236	.302	.478	.780	960	139.8	.343	113	108.5
25	Mickey Mantle M. Mantle	0.07	8,102	536	2,401	1,676	2,415	344	72	1,509	1,733	13	1,710	153	38	9,909	4,511	952	14	47	126	113	.298	.421	.557	.977	1941	840	.428	170	821.8