James Harden has the highest plus/minus in a game with 40+ points, at +50 against the Hawks on November 30, 2019.

Interpreted as:

highest +/- by a player in a regular-season game with 40 or more points

	NAME	+/-	PTS	DATE	TM		OPP	MIN	REB	AST	STL	BLK	FGM	FGA	FG%	3PM	3PA	3P%	FTM	FTA	FT%	TS%	OREB	DREB	TOV	PF
1	James Harden J. Harden	+50	60	11/30/2019	HOU	vs	ATL	31	3	8	3	1	16	24	66.7	8	14	57.1	20	23	87.0	87.9	0	3	5	3
2	Kemba Walker K. Walker	+47	46	3/22/2018	CHA	vs	MEM	28	3	4	1	0	13	18	72.2	10	14	71.4	10	10	100.0	102.7	0	3	2	1
3	Trey Murphy III T. Murphy III	+44	41	3/12/2023	NOP	vs	POR	30	7	1	1	1	13	20	65.0	9	14	64.3	6	6	100.0	90.5	1	6	1	2
4	Shai Gilgeous-Alexander S. Gilgeous-Alexander	+42	50	2/5/2025	OKC	vs	PHX	34	8	5	2	1	18	29	62.1	3	7	42.9	11	12	91.7	72.9	2	6	1	3
5	Stephen Curry S. Curry	+42	43	1/28/2017	GSW	vs	LAC	29	9	6	0	0	15	23	65.2	9	15	60.0	4	4	100.0	86.8	0	9	2	1
6	Kobe Bryant K. Bryant	+40	56	1/14/2002	LAL	vs	MEM	34	5	4	1	0	21	34	61.8	3	6	50.0	11	12	91.7	71.3	3	2	0	1
7	Kawhi Leonard K. Leonard	+39	43	1/14/2020	LAC	vs	CLE	29	3	4	2	1	14	22	63.6	6	10	60.0	9	10	90.0	81.4	0	3	1	0
8	Shai Gilgeous-Alexander S. Gilgeous-Alexander	+38	42	2/4/2023	OKC	vs	HOU	30	4	6	3	2	14	23	60.9	0	2	0.0	14	15	93.3	70.9	0	4	0	3
9	Klay Thompson K. Thompson	+38	52	1/23/2015	GSW	vs	SAC	33	2	5	4	2	16	25	64.0	11	15	73.3	9	10	90.0	88.4	0	2	4	3
10	Amar'e Stoudemire A. Stoudemire	+38	42	2/18/2009	PHX	@	LAC	36	11	1	0	0	15	20	75.0	0	0		12	13	92.3	81.6	5	6	1	3
11	Gilbert Arenas G. Arenas	+38	40	11/8/2006	WAS	vs	IND	32	1	4	3	0	14	20	70.0	4	6	66.7	8	9	88.9	83.5	0	1	2	3
12	Brandon Ingram B. Ingram	+37	41	2/5/2024	NOP	vs	TOR	30	6	9	0	1	16	21	76.2	8	11	72.7	1	1	100.0	95.6	1	5	0	1
13	Trae Young T. Young	+37	41	2/26/2022	ATL	vs	TOR	37	4	11	1	1	17	24	70.8	1	4	25.0	6	6	100.0	77.0	1	3	4	3
14	Klay Thompson K. Thompson	+37	60	12/5/2016	GSW	vs	IND	29	2	1	0	0	21	33	63.6	8	14	57.1	10	11	90.9	79.3	0	2	0	0
15	Klay Thompson K. Thompson	+37	43	12/16/2015	GSW	vs	PHX	31	3	2	1	0	15	22	68.2	8	13	61.5	5	5	100.0	88.8	0	3	1	0
16	Kobe Bryant K. Bryant	+37	51	2/12/2003	LAL	@	DEN	31	3	2	2	0	15	28	53.6	3	8	37.5	18	20	90.0	69.3	0	3	0	1
17	Kobe Bryant K. Bryant	+37	42	2/11/2003	LAL	vs	DEN	31	2	5	4	0	12	20	60.0	1	3	33.3	17	21	81.0	71.8	0	2	1	0
18	Zach LaVine Z. LaVine	+36	42	2/24/2025	SAC	vs	CHA	31	3	2	1	0	16	19	84.2	8	9	88.9	2	3	66.7	103.3	0	3	3	0
19	Joel Embiid J. Embiid	+36	42	12/16/2023	PHI	@	CHA	30	15	3	1	2	18	23	78.3	0	1	0.0	6	6	100.0	81.9	0	15	4	2
20	Jayson Tatum J. Tatum	+36	40	3/30/2023	BOS	@	MIL	31	8	1	0	0	12	18	66.7	8	10	80.0	8	8	100.0	92.9	1	7	0	1
21	Kyrie Irving K. Irving	+36	60	3/15/2022	BKN	@	ORL	35	6	4	4	1	20	31	64.5	8	12	66.7	12	13	92.3	81.7	2	4	1	3
22	Jaylen Brown J. Brown	+36	40	4/15/2021	BOS	@	LAL	32	9	3	1	0	17	20	85.0	3	5	60.0	3	3	100.0	93.8	0	9	6	2
23	Zach LaVine Z. LaVine	+36	40	3/16/2021	CHI	vs	OKC	31	3	2	1	0	15	20	75.0	7	12	58.3	3	3	100.0	93.8	1	2	1	2
24	James Harden J. Harden	+36	42	11/9/2019	HOU	@	CHI	36	10	9	2	0	12	27	44.4	9	19	47.4	9	11	81.8	66.0	1	9	6	1
25	Donovan Mitchell D. Mitchell	+36	40	2/2/2018	UTA	@	PHX	33	5	6	2	0	14	19	73.7	7	9	77.8	5	5	100.0	94.3	1	4	2	0