The War of 18-49, Magnum P.I.

An Underwhelming Monday Rookie

Just two years after returning to its traditional two hours of Monday comedy, in fall 2018 CBS gave up on the plan once again and returned to drama programming at 9/8c. But newbie Magnum P.I. immediately looked like a much weaker option than the last drama they used for this role (Scorpion in fall 2014). With help from The Big Bang Theory (2.5) and Young Sheldon (1.7) on Premiere Monday, Magnum mustered up a 1.1 demo, and it fell to a 0.9 the next week when the regular Monday comedy hour took over. It mostly pulled 0.8's going forward that season, even hitting some 0.7's down the stretch. And while Scorpion had usually built from the comedy hour at 9/8c, Magnum generally matched it at best, and was often down a bit. Magnum ended up only barely improving on a very weak comedy hour from the previous season, and didn't seem to be the answer for the Monday 9/8c hour.

New Life on Friday 

But it got renewed and sent off to Friday, where it would have to fit in on a night that already had three established properties in MacGyver, Hawaii Five-0 and Blue Bloods. For fall 2019, Magnum aired at 9/8c while Hawaii moved to 8/7c. While Magnum still wasn't anything special, and usually lost a little bit of Hawaii's demo, it was at least more competitive with the standard historically. And it looked better following a winter hiatus, matching and sometimes outrating its MacGyver lead-in during the spring.

With Hawaii Five-0's cancellation coming into the 2020-21 season, CBS had a much clearer trio of Friday dramas, and they were consistently steady year-to-year in Plus. That included Magnum continuing to match or edge MacGyver, and it actually tied what Hawaii Five-0 had done at 9/8c during Magnum's winter hiatus the previous season. The cancellation of MacGyver gave Magnum a much more volatile lead-in situation in season four, but it looked solid for the fall/winter (after S.W.A.T. and Undercover Boss) before falling off a bit when CBS premiered the flop reality series Come Dance with Me.

But for a third straight year, CBS swung the axe on a solid Friday night performer, and this time it was Magnum P.I. that got cancelled. As well as this lineup has seemed to stack up with CBS Fridays of the past, it seems pretty clear at this point that it's not good enough for CBS to keep intact. Perhaps CBS just doesn't want to overspend on veteran dramas when so many shows have proven capable of big numbers here (including shows that struggled on weeknights like Magnum and S.W.A.T.). This fall, CBS will replace Magnum with the new firefighter drama Fire Country. But unlike MacGyver, Magnum was able to find a second home, and has been picked up for two short seasons at NBC.

Adults 18-49 info by season:

Seas	Year	Slot	Avg	y2y	Lo	Hi	Results	Grade
1	2018-19	Monday 9:00	0.85		0.7	2.4	detail	C
2	2019-20	Friday 9:00	0.65	-24%	0.5	0.8	detail	B
3	2020-21		Friday 9:00	0.52	-21%	0.4	0.6	detail	B
4	2021-22		Friday 9:00	0.42	-19%	0.3	0.5	detail	B
5	Winter Spring 2023	Sunday 9:00	0.27	-35%	0.2	0.4	detail	C
6	2023-24	Wednesday 9:00	0.26	-4%	0.2	0.3	detail	C+

Historical-adjusted ratings by season:

Seas	Year	A18-49+	Label	Now24	y2y	Lo	Hi	Premiere	Finale
1	2018-19	90	marginal	0.34		69	254	122	72
2	2019-20	79	hit(Fri)	0.30	-12%	67	104	70	73
3	2020-21	80	hit(Fri)	0.30	+1%	64	93	78	64
4	2021-22	82	hit(Fri)	0.31	+2%	61	98	76	67
5	Winter Spring 2023	64	flop	0.24	-22%	47	84	84	59
6	2023-24	68	flop	0.26	+7%	55	84	84	69
AVERAGE:		AVERAGE:	77	hit(Fri)
CAREER:		CAREER:	463	utility

The War of 18-49 chronicles the ratings history of veteran primetime series. For more, see the Index.