Since 2017-18, the Boston Celtics have the best record by a team as underdogs, with a record of 54-70.

what team has the best record as an underdog since 2017-18

TEAM	REC	GP	W%	MPG	PPG	RPG	APG	SPG	BPG	TPG	FGM	FGA	FG%	3PM	3PA	3P%	FTM	FTA	FT%	MIN	PTS	REB	AST	STL	BLK	TOV	PF
Boston Celtics	54-70	124	.435	242.4	108.9	44.6	23.2	7.4	4.7	12.9	39.8	88.7	44.8	12.7	34.9	36.3	16.7	21.2	78.8	30,060	13,500	5,533	2,882	920	578	1,595	2,490
Miami Heat	85-127	212	.401	241.5	105.8	42.8	24.7	7.4	4.2	13.6	39.1	86.3	45.3	12.5	34.6	36.0	15.1	19.9	76.1	51,205	22,421	9,068	5,227	1,579	883	2,876	4,156
Denver Nuggets	60-91	151	.397	241.7	108.9	42.9	25.8	7.4	4.3	13.3	40.9	87.9	46.5	11.5	32.1	35.8	15.6	20.0	77.9	36,490	16,442	6,479	3,901	1,114	647	2,002	2,915
Oklahoma City Thunder	111-183	294	.378	241.9	108.2	44.7	22.4	7.6	4.5	13.6	39.7	89.2	44.5	11.7	34.4	34.1	17.0	22.3	76.6	71,110	31,813	13,139	6,586	2,244	1,311	4,005	5,713
Los Angeles Lakers	98-164	262	.374	242.8	111.4	44.7	24.5	7.2	4.8	14.3	41.5	88.9	46.7	10.7	31.2	34.4	17.6	23.8	74.0	63,605	29,185	11,700	6,406	1,892	1,264	3,743	5,169
Philadelphia 76ers	64-109	173	.370	241.6	108.1	43.4	23.4	7.9	4.9	13.4	39.8	87.5	45.5	11.3	32.1	35.2	17.2	21.9	78.4	41,795	18,699	7,509	4,053	1,361	851	2,312	3,586
Indiana Pacers	106-182	288	.368	240.8	111.9	41.8	25.8	7.9	5.1	13.2	42.0	89.9	46.7	11.6	32.0	36.3	16.2	20.8	77.7	69,345	32,234	12,046	7,418	2,286	1,463	3,794	5,878
New Orleans Pelicans	103-185	288	.358	241.2	111.3	45.0	25.6	7.6	4.5	14.1	41.6	89.4	46.5	11.2	31.6	35.4	16.9	22.3	75.9	69,470	32,063	12,956	7,379	2,187	1,302	4,066	5,776
Sacramento Kings	116-219	335	.346	241.6	109.2	42.5	24.2	7.6	4.1	13.4	41.1	89.3	46.1	11.6	32.0	36.1	15.4	20.5	74.9	80,925	36,572	14,236	8,105	2,538	1,358	4,481	6,831
L.A. Clippers	68-129	197	.345	241.4	108.8	43.7	22.4	6.8	4.3	13.3	39.7	87.1	45.5	10.9	30.2	36.2	18.5	24.0	77.0	47,555	21,425	8,617	4,414	1,342	852	2,611	4,073
Toronto Raptors	74-141	215	.344	241.7	110.1	42.9	24.5	8.1	4.7	12.8	40.8	89.6	45.5	12.1	34.3	35.2	16.4	21.0	78.0	51,975	23,661	9,229	5,278	1,750	1,003	2,751	4,344
Memphis Grizzlies	110-210	320	.344	241.2	106.5	43.0	24.7	8.2	5.2	13.7	39.4	88.0	44.8	11.1	31.8	35.0	16.5	21.4	77.1	77,175	34,075	13,764	7,904	2,638	1,653	4,375	6,702
Utah Jazz	67-128	195	.344	241.9	110.7	43.9	24.7	7.0	4.9	14.7	40.4	87.9	45.9	12.6	35.4	35.5	17.4	21.9	79.3	47,175	21,582	8,556	4,817	1,374	961	2,874	3,874
Brooklyn Nets	102-195	297	.343	241.7	109.9	44.0	24.3	6.5	4.5	13.3	40.0	88.8	45.0	12.7	35.5	35.7	17.2	22.3	77.2	71,780	32,637	13,076	7,216	1,932	1,327	3,962	6,062
Dallas Mavericks	85-168	253	.336	241.3	107.7	42.5	22.8	6.5	3.8	12.4	39.0	86.7	45.0	13.1	36.9	35.6	16.6	21.7	76.4	61,045	27,244	10,755	5,769	1,634	973	3,128	5,027
Milwaukee Bucks	34-68	102	.333	242.0	107.2	42.5	23.0	8.0	4.3	13.8	39.4	87.6	44.9	12.2	34.8	35.1	16.2	21.0	77.3	24,680	10,933	4,333	2,349	815	439	1,404	2,001
Minnesota Timberwolves	94-189	283	.332	241.9	111.8	42.8	24.3	8.1	5.0	13.6	40.9	89.6	45.7	12.0	33.9	35.4	17.9	23.4	76.7	68,470	31,650	12,119	6,865	2,295	1,405	3,850	5,961
Golden State Warriors	59-126	185	.319	241.2	109.6	43.3	26.2	7.4	4.4	14.5	40.1	88.2	45.4	12.7	35.7	35.7	16.7	21.0	79.4	44,625	20,271	8,012	4,848	1,361	817	2,680	3,846
New York Knicks	110-242	352	.313	241.6	106.4	44.9	21.9	6.9	4.4	13.1	39.3	87.9	44.7	10.7	30.5	35.3	17.0	22.6	75.3	85,030	37,436	15,800	7,698	2,412	1,559	4,607	7,309
Atlanta Hawks	105-233	338	.311	241.4	110.5	43.6	24.5	7.5	4.5	14.4	40.5	89.4	45.3	12.2	34.4	35.4	17.3	22.0	78.9	81,595	37,349	14,727	8,283	2,532	1,515	4,859	7,018
Washington Wizards	111-247	358	.310	241.3	112.1	42.2	25.6	7.5	4.4	13.3	41.8	89.5	46.7	11.2	31.7	35.2	17.4	22.5	77.3	86,395	40,137	15,124	9,171	2,678	1,569	4,776	7,328
Phoenix Suns	83-186	269	.309	241.8	108.3	42.9	24.1	7.6	4.5	14.5	40.0	88.0	45.5	10.5	30.2	34.7	17.9	22.8	78.4	65,035	29,144	11,543	6,472	2,049	1,221	3,904	5,999
Orlando Magic	124-278	402	.308	241.0	105.6	43.4	23.3	7.2	4.8	13.3	39.0	87.8	44.4	11.1	32.5	34.1	16.5	21.4	77.3	96,880	42,442	17,446	9,384	2,911	1,911	5,343	7,762
Cleveland Cavaliers	94-211	305	.308	241.6	106.0	42.7	23.0	7.0	3.5	13.5	39.4	86.6	45.5	11.0	31.2	35.2	16.3	21.1	76.9	73,675	32,322	13,011	7,024	2,139	1,053	4,131	5,730
Charlotte Hornets	118-266	384	.307	241.7	107.3	42.8	24.5	7.2	4.5	13.1	39.5	88.3	44.8	11.9	33.9	35.1	16.4	21.7	75.7	92,810	41,203	16,451	9,423	2,769	1,731	5,028	7,196