LeBron James had the most games by a player younger than 22 in the playoffs with 30+ points, with 8 games.

most 30 point playoff games before turning 22

Interpreted as:

most 30 or more point playoff games before turning 22 years old by a player

NAME	GP	PTS	MPG	PPG	RPG	APG	SPG	BPG	TPG	FGM	FGA	FG%	3PM	3PA	3P%	FTM	FTA	FT%	MIN	REB	AST	STL	BLK	TOV	PF	+/-
LeBron James	8	282	47.8	35.3	8.3	6.1	1.1	0.4	4.5	12.8	24.9	51.3	2.0	5.3	38.1	7.8	10.1	76.5	382	66	49	9	3	36	29	-11
Anthony Edwards	5	177	42.4	35.4	4.4	5.0	2.0	2.2	2.0	11.6	23.8	48.7	4.4	10.8	40.7	7.8	9.0	86.7	212	22	25	10	11	10	14	+4
Kobe Bryant	4	132	42.0	33.0	3.8	3.3	2.5	0.8	3.3	12.5	24.8	50.5	2.8	5.3	52.4	5.3	7.3	72.4	168	15	13	10	3	13	16	-15
Paolo Banchero	3	108	36.3	36.0	12.7	3.7	1.3	0.3	3.3	12.3	26.0	47.4	3.7	7.3	50.0	7.7	9.3	82.1	109	38	11	4	1	10	8	+25
Luka Doncic	3	123	41.9	41.0	11.0	10.3	2.0	0.3	7.7	15.3	26.7	57.5	3.3	8.3	40.0	7.0	9.3	75.0	126	33	31	6	1	23	9	-12
Derrick Rose	3	98	45.1	32.7	3.0	8.0	0.7	0.0	2.3	12.3	24.0	51.4	0.7	1.7	40.0	7.3	8.0	91.7	135	9	24	2	0	7	7	+8
Tracy McGrady	3	110	45.0	36.7	7.7	8.3	1.7	1.7	2.7	13.7	32.3	42.3	0.7	2.7	25.0	8.7	10.0	86.7	135	23	25	5	5	8	8	-17
Tyrese Maxey	2	72	40.9	36.0	3.5	1.5	1.0	0.0	0.0	13.0	21.5	60.5	3.0	6.0	50.0	7.0	8.0	87.5	82	7	3	2	0	0	1	+10
Donovan Mitchell	2	71	39.5	35.5	5.5	3.0	0.5	0.5	2.5	13.5	27.0	50.0	4.0	8.0	50.0	4.5	5.0	90.0	79	11	6	1	1	5	8	+16
Jaylen Brown	2	64	37.3	32.0	6.5	1.0	1.5	0.0	1.0	12.5	23.0	54.3	5.0	10.0	50.0	2.0	3.0	66.7	75	13	2	3	0	2	4	+27
Ja Morant	1	47	43.4	47.0	4.0	7.0	0.0	0.0	4.0	15.0	26.0	57.7	2.0	7.0	28.6	15.0	20.0	75.0	43	4	7	0	0	4	3	-6
Tyler Herro	1	37	35.7	37.0	6.0	3.0	0.0	0.0	1.0	14.0	21.0	66.7	5.0	10.0	50.0	4.0	4.0	100.0	36	6	3	0	0	1	1	-4
Luguentz Dort	1	30	34.7	30.0	4.0	1.0	0.0	1.0	4.0	10.0	21.0	47.6	6.0	12.0	50.0	4.0	6.0	66.7	35	4	1	0	1	4	5	0
Bradley Beal	1	34	44.3	34.0	6.0	7.0	3.0	1.0	3.0	11.0	25.0	44.0	4.0	8.0	50.0	8.0	9.0	88.9	44	6	7	3	1	3	0	0
Kevin Durant	1	32	40.5	32.0	8.0	1.0	2.0	4.0	8.0	12.0	26.0	46.2	3.0	6.0	50.0	5.0	6.0	83.3	41	8	1	2	4	8	3	0
Brandon Jennings	1	34	40.2	34.0	3.0	3.0	1.0	0.0	3.0	14.0	25.0	56.0	4.0	6.0	66.7	2.0	4.0	50.0	40	3	3	1	0	3	3	-7
Daniel Gibson	1	31	29.0	31.0	6.0	2.0	0.0	0.0	2.0	7.0	9.0	77.8	5.0	5.0	100.0	12.0	15.0	80.0	29	6	2	0	0	2	5	+19
Tony Parker	1	30	41.0	30.0	2.0	5.0	3.0	0.0	1.0	13.0	23.0	56.5	2.0	4.0	50.0	2.0	2.0	100.0	41	2	5	3	0	1	1	+12
Tim Duncan	1	32	37.0	32.0	10.0	1.0	1.0	2.0	3.0	12.0	21.0	57.1	0.0	0.0		8.0	14.0	57.1	37	10	1	1	2	3	3	+12
Magic Johnson	1	42	47.0	42.0	15.0	7.0	3.0	1.0	5.0	14.0	23.0	60.9	0.0	1.0	0.0	14.0	14.0	100.0	47	15	7	3	1	5	3
Alvan Adams	1	33	40.0	33.0	14.0	2.0	2.0	1.0		14.0	25.0	56.0				5.0	6.0	83.3	40	14	2	2	1		3
Carl Braun	1	30		30.0						10.0						10.0	12.0	83.3							4