Tim Duncan has the highest career plus/minus by a player younger than 30, at +4841.

Interpreted as:

best plus minus by a player before age 30

	NAME	+/-	GP	MPG	PPG	RPG	APG	SPG	BPG	FGM	FGA	FG%	3PM	3PA	3P%	FTM	FTA	FT%	TS%	OREB	DREB	TPG	MIN	PTS	REB	AST	STL	BLK	TOV	PF
1	Tim Duncan T. Duncan	+4841	666	37.9	22.1	12.0	3.1	0.8	2.5	8.4	16.7	50.5	0.0	0.2	20.4	5.2	7.5	68.5	55.1	3.2	8.8	2.9	25,240	14,689	8,020	2,092	529	1,650	1,928	1,833
2	LeBron James L. James	+4650	871	39.5	27.4	7.2	6.9	1.7	0.8	9.9	19.8	49.6	1.4	4.0	34.2	6.4	8.5	74.7	58.1	1.2	6.0	3.3	34,364	23,901	6,239	6,011	1,483	698	2,906	1,615
3	Dirk Nowitzki D. Nowitzki	+4402	758	36.5	22.4	8.6	2.7	0.9	1.0	7.7	16.4	47.1	1.3	3.5	37.9	5.6	6.5	87.0	58.3	1.3	7.3	1.9	27,642	16,990	6,501	2,050	715	794	1,461	2,002
4	Tony Parker T. Parker	+4173	806	32.9	16.8	3.0	5.9	1.0	0.1	6.7	13.6	49.2	0.4	1.4	31.0	3.0	4.1	73.8	54.7	0.4	2.6	2.5	26,514	13,576	2,447	4,748	782	60	2,035	1,462
5	Stephen Curry S. Curry	+4017	624	34.5	23.1	4.4	6.8	1.8	0.2	8.0	16.8	47.7	3.4	7.8	43.6	3.6	4.0	90.3	62.1	0.7	3.7	3.2	21,503	14,405	2,756	4,226	1,108	128	1,970	1,554
6	Nikola Jokić N. Jokić	+3948	724	31.5	21.5	10.9	7.1	1.3	0.7	8.3	14.8	55.9	1.1	3.0	36.0	3.9	4.7	82.7	63.7	2.7	8.2	2.9	22,830	15,597	7,866	5,169	911	523	2,100	1,942
7	Kawhi Leonard K. Leonard	+3689	576	31.3	19.2	6.4	2.9	1.8	0.6	6.9	14.0	49.3	1.5	3.9	38.4	3.9	4.5	85.8	60.0	1.2	5.2	1.6	18,024	11,085	3,689	1,672	1,013	367	933	988
8	Klay Thompson K. Thompson	+3676	615	33.1	19.5	3.5	2.3	0.9	0.5	7.3	16.0	45.9	2.9	7.0	41.9	1.9	2.3	84.8	57.5	0.4	3.0	1.7	20,340	11,995	2,130	1,416	561	332	1,053	1,313
9	Jayson Tatum J. Tatum	+3645	585	34.5	23.6	7.3	3.8	1.1	0.7	8.2	17.8	45.9	2.6	7.1	37.0	4.5	5.4	84.0	58.3	0.9	6.5	2.4	20,184	13,784	4,293	2,243	640	384	1,389	1,232
10	Draymond Green D. Green	+3373	576	28.1	9.0	6.9	5.0	1.4	1.1	3.3	7.5	43.5	0.9	2.8	31.9	1.6	2.2	71.0	53.1	1.1	5.8	2.1	16,200	5,170	3,966	2,855	789	609	1,187	1,592
11	Kobe Bryant K. Bryant	+3229	866	36.5	25.0	5.3	4.6	1.5	0.6	8.6	19.0	45.3	1.3	3.7	34.0	6.5	7.7	83.9	55.7	1.2	4.1	2.9	31,571	21,619	4,590	4,002	1,321	507	2,542	2,338
12	James Harden J. Harden	+3136	765	34.1	24.3	5.2	6.2	1.6	0.5	7.2	16.2	44.3	2.6	7.3	36.5	7.3	8.5	85.7	60.9	0.8	4.5	3.6	26,105	18,627	4,000	4,743	1,189	383	2,770	1,977
13	Kevin Durant K. Durant	+3022	771	37.1	27.1	7.1	3.9	1.2	1.1	9.2	18.8	49.0	1.9	4.8	38.4	6.9	7.8	88.2	61.1	0.8	6.4	3.1	28,603	20,913	5,495	3,029	890	857	2,428	1,463
14	Dwight Howard D. Howard	+2945	824	35.6	18.1	12.7	1.5	1.0	2.1	6.4	11.1	57.9	0.0	0.1	10.4	5.2	9.0	57.3	59.8	3.5	9.2	3.1	29,310	14,876	10,504	1,250	810	1,739	2,540	2,724
15	Russell Westbrook R. Westbrook	+2893	755	34.3	23.0	6.6	8.2	1.7	0.3	8.0	18.4	43.6	1.1	3.4	30.9	5.9	7.2	81.2	53.2	1.7	5.0	4.0	25,919	17,353	5,011	6,175	1,315	218	3,030	1,837
16	Chris Paul C. Paul	+2886	699	36.2	18.7	4.4	9.9	2.3	0.1	6.6	13.9	47.4	1.1	2.9	36.4	4.4	5.2	86.1	57.8	0.7	3.7	2.4	25,305	13,060	3,070	6,950	1,641	69	1,683	1,724
17	Donovan Mitchell D. Mitchell	+2741	562	33.9	25.0	4.3	4.7	1.4	0.3	8.8	19.6	45.1	3.0	8.3	36.7	4.2	5.0	84.0	57.2	0.8	3.5	2.7	19,033	14,022	2,435	2,656	772	180	1,525	1,355
18	Rudy Gobert R. Gobert	+2730	611	30.0	12.4	11.7	1.3	0.7	2.2	4.6	7.0	65.3	0.0	0.0	0.0	3.3	5.1	63.8	67.1	3.3	8.3	1.6	18,300	7,592	7,119	807	412	1,357	1,008	1,579
19	Shaquille O'Neal S. O'Neal	+2725	359	37.8	28.0	12.2	3.2	0.6	2.6	11.1	19.4	57.4	0.0	0.0	0.0	5.7	10.9	52.1	57.7	3.8	8.3	2.8	13,563	10,041	4,366	1,140	233	920	1,000	1,172
20	Giannis Antetokounmpo G. Antetokounmpo	+2695	811	32.8	23.6	9.8	4.9	1.1	1.2	8.6	15.7	54.7	0.7	2.3	28.6	5.7	8.2	69.9	61.0	1.8	8.0	3.0	26,606	19,121	7,953	3,981	913	1,011	2,446	2,426
21	Rasheed Wallace R. Wallace	+2582	567	35.3	16.7	7.0	2.0	1.0	1.3	6.6	13.4	49.4	0.7	2.1	33.4	2.7	3.8	71.3	55.2	1.7	5.3	1.9	20,024	9,441	3,958	1,144	580	743	1,066	1,688
22	Joel Embiid J. Embiid	+2514	428	32.0	27.8	11.2	3.6	0.9	1.7	9.2	18.2	50.4	1.2	3.4	33.9	8.3	10.1	82.5	61.4	2.3	8.9	3.4	13,682	11,919	4,786	1,547	390	714	1,461	1,313
23	Blake Griffin B. Griffin	+2459	595	35.1	21.8	9.0	4.4	0.9	0.5	8.2	16.3	50.3	0.6	1.7	34.0	4.8	6.9	69.1	56.3	2.2	6.8	2.6	20,871	12,992	5,356	2,647	540	312	1,557	1,727
24	Kevin Garnett K. Garnett	+2444	771	39.2	21.4	11.8	4.8	1.4	1.7	8.5	17.3	49.3	0.2	0.6	29.8	4.2	5.4	77.6	54.4	2.9	8.9	2.7	30,247	16,502	9,066	3,688	1,107	1,319	2,072	1,982
25	Serge Ibaka S. Ibaka	+2365	753	28.7	12.3	7.3	0.7	0.4	2.2	5.1	10.0	51.4	0.6	1.7	35.7	1.5	1.9	76.1	57.0	2.2	5.1	1.3	21,625	9,298	5,492	545	323	1,626	980	2,126