The 9-8

In its original American broadcast, "The 9-8" was seen by an estimated 2.28 million household viewers and gained a 1.0/3 ratings share among adults aged 18–49, according to Nielsen Media Research.[1] This was a slight increase in viewership from the previous episode, which was watched by 2.24 million viewers with a 1.0/3 in the 18-49 demographics.[2] This means that 1.0 percent of all households with televisions watched the episode, while 3 percent of all households watching television at that time watched it. With these ratings, Brooklyn Nine-Nine was the second most watched show on FOX for the night, beating The Grinder and Grandfathered, but behind New Girl, third on its timeslot and tenth for the night, behind Hollywood Game Night, Fresh Off the Boat, Limitless, New Girl, The Flash, Chicago Med, Chicago Fire, NCIS: New Orleans, and NCIS.

"The 9-8" received critical acclaim from critics. LaToya Ferguson of The A.V. Club gave the episode an "A" grade and wrote, "It feels safe to say this three seasons in: The men and women of the Nine-Nine are very much set in their ways. Sure, there's character growth, which is always a beautiful thing to see in the series. But they really don't react well to change, temporary or otherwise."[3] Allie Pape from Vulture gave the show a perfect 5 star rating out of 5 and wrote, "Given the massive episode orders they must fill, network sitcom writers are often tempted to subdivide their stories into neat A-, B-, and C-plots that don't relate thematically or dovetail together. That's why it’s nice to see an occasional episode like 'The 9-8' to come in and shake things up."[4]

Alan Sepinwall of HitFix wrote, "I don't always love Brooklyn episodes where the squadroom fills up past capacity, as the show tends to get too frantic for its own good in those stories. 'The 9-8' worked, though, because it dealt with the invasion from the other precinct on two levels."[5] Andy Crump of Paste gave the episode a 9.0 rating and wrote, "So you kind of know that 'The 9-8' is going to end in altercations and animosity, though watching the set turn into a riff on Blazing Saddles remains nothing short of an acrimonious delight. It is the perfect payoff to an episode that builds pent up frustrations across each of its plot lines, though really the A/B/C structure is mostly boiled down to A and B."[6]