Anthony Edwards has the most games by a player younger than 21 with 5+ three-pointers, with 23 games.

Interpreted as:

most regular-season games with 5 or more 3pm before turning 21 years old by a player

	NAME	GP	3PM	MPG	PPG	RPG	APG	SPG	BPG	FGM	FGA	FG%	3PA	3P%	FTM	FTA	FT%	TS%	OREB	DREB	TPG	MIN	PTS	REB	AST	STL	BLK	TOV	PF	+/-
1	Anthony Edwards A. Edwards	23	134	35.2	31.2	4.9	4.0	1.6	0.7	11.0	20.8	52.7	11.1	52.3	3.4	4.3	79.8	68.7	0.6	4.3	2.7	809	717	112	92	37	15	61	49	+190
2	Jalen Green J. Green	18	102	34.3	29.1	3.1	3.0	0.8	0.4	10.1	19.0	52.9	10.7	53.1	3.3	4.2	78.7	69.7	0.6	2.4	2.3	617	523	55	54	14	7	42	29	-5
3	LaMelo Ball L. Ball	17	101	33.2	27.1	6.7	7.7	1.9	0.4	9.1	18.2	49.7	10.2	58.4	3.1	3.5	88.1	68.6	1.5	5.2	3.5	565	461	114	131	33	7	60	62	+185
4	Luka Dončić L. Dončić	14	77	33.2	34.6	10.4	9.0	0.9	0.2	11.1	21.8	51.1	11.2	49.0	6.8	9.3	73.1	66.8	1.7	8.7	3.9	465	484	146	126	12	3	54	30	+172
5	Victor Wembanyama V. Wembanyama	11	65	36.3	34.6	12.1	4.7	0.9	4.5	12.1	22.2	54.5	12.1	48.9	4.5	5.7	79.4	70.1	1.8	10.3	4.5	399	381	133	52	10	49	49	20	+101
6	Jamal Murray J. Murray	10	52	33.5	26.9	4.2	3.0	1.0	0.4	9.4	16.7	56.3	7.8	66.7	2.9	3.5	82.9	73.7	1.2	3.0	2.5	335	269	42	30	10	4	25	31	+94
7	Keyonte George K. George	9	51	33.5	27.0	3.7	5.1	0.6	0.3	9.0	16.4	54.7	10.2	55.4	3.3	4.2	78.9	73.8	0.0	3.7	2.8	301	243	33	46	5	3	25	20	+18
8	Coby White C. White	8	49	30.4	28.3	4.5	2.5	1.0	0.1	9.5	18.1	52.4	11.0	55.7	3.1	3.4	92.6	72.0	0.5	4.0	2.6	243	226	36	20	8	1	21	18	+33
9	Nick Smith Jr. N. Smith Jr.	7	38	32.1	22.0	3.6	3.7	0.6	0.0	7.6	13.7	55.2	8.4	64.4	1.4	1.4	100.0	76.7	0.4	3.1	1.9	225	154	25	26	4	0	13	10	-37
10	Cade Cunningham C. Cunningham	7	37	35.8	28.9	6.3	6.0	1.9	1.4	11.0	20.3	54.2	9.4	56.1	1.6	2.0	78.6	68.2	0.7	5.6	5.1	251	202	44	42	13	10	36	18	-32
11	Jaren Jackson Jr. J. Jackson Jr.	7	42	30.0	26.7	4.0	0.9	0.4	0.3	8.7	15.6	56.0	10.3	58.3	3.3	4.9	67.6	75.4	0.9	3.1	1.9	210	187	28	6	3	2	13	27	-42
12	Trae Young T. Young	7	40	38.6	33.9	3.1	10.0	0.9	0.1	12.0	23.3	51.5	11.6	49.4	4.1	5.0	82.9	66.4	0.4	2.7	3.9	270	237	22	70	6	1	27	15	-11
13	Devin Booker D. Booker	7	39	37.7	30.9	2.9	2.4	0.9	0.0	10.3	20.4	50.3	9.4	59.1	4.7	5.6	84.6	67.4	0.3	2.6	3.6	264	216	20	17	6	0	25	28	-10
14	Bradley Beal B. Beal	7	39	38.8	27.4	4.3	3.3	0.4	0.3	9.9	18.6	53.1	7.6	73.6	2.1	2.1	100.0	70.3	1.1	3.1	2.3	272	192	30	23	3	2	16	13	+26
15	LeBron James L. James	7	40	42.6	40.7	6.3	5.4	2.3	0.1	14.1	25.7	55.0	9.4	60.6	6.7	7.6	88.7	70.1	1.0	5.3	3.3	298	285	44	38	16	1	23	15	+24
16	Kon Knueppel K. Knueppel	6	33	35.4	25.2	5.3	3.3	0.7	0.3	8.7	16.5	52.5	10.8	50.8	2.3	2.5	93.3	71.5	1.2	4.2	1.8	213	151	32	20	4	2	11	14	-10
17	Zaccharie Risacher Z. Risacher	6	32	31.2	30.8	4.5	1.3	2.0	0.8	11.2	16.8	66.3	9.0	59.3	3.2	5.2	61.3	80.7	1.2	3.3	0.8	187	185	27	8	12	5	5	12	+74
18	Kevin Huerter K. Huerter	6	31	35.0	20.5	3.0	3.2	1.2	0.5	7.3	11.5	63.8	7.5	68.9	0.7	1.0	66.7	85.8	0.8	2.2	2.7	210	123	18	19	7	3	16	19	+34
19	GG Jackson	5	31	34.3	28.4	3.4	1.0	1.0	0.6	9.4	17.0	55.3	11.4	54.4	3.4	4.8	70.8	74.3	1.0	2.4	2.2	171	142	17	5	5	3	11	15	+26
20	RJ Barrett	5	27	37.8	24.4	6.2	2.6	0.4	0.4	8.0	17.4	46.0	8.8	61.4	3.0	3.4	88.2	64.6	1.0	5.2	2.6	189	122	31	13	2	2	13	9	-28
21	Tyler Herro T. Herro	5	28	30.5	22.6	4.8	1.4	0.4	0.0	7.8	15.0	52.0	8.8	63.6	1.4	1.4	100.0	72.4	0.2	4.6	1.2	152	113	24	7	2	0	6	7	+35
22	Lauri Markkanen L. Markkanen	5	28	31.1	26.2	7.6	0.6	0.4	0.6	8.6	15.2	56.6	9.2	60.9	3.4	4.0	85.0	77.2	1.0	6.6	1.0	156	131	38	3	2	3	5	5	+8
23	D'Angelo Russell D. Russell	5	32	33.2	28.2	5.6	4.8	1.6	0.0	9.8	18.8	52.1	11.2	57.1	2.2	3.4	64.7	69.5	0.8	4.8	2.2	166	141	28	24	8	0	11	5	+32
24	Eric Gordon E. Gordon	5	26	42.0	31.6	4.4	4.0	1.6	0.6	10.4	18.0	57.8	7.2	72.2	5.6	7.0	80.0	75.0	1.0	3.4	2.0	210	158	22	20	8	3	10	8	-5
25	Stephon Marbury S. Marbury	5	30	39.6	27.8	2.8	8.6	0.4	0.2	8.8	17.2	51.2	9.6	62.5	4.2	5.6	75.0	70.7	0.6	2.2	4.0	198	139	14	43	2	1	20	20	+17