The four-show crossover The CW pulled off this week gave a ratings bounce to every show — something the network and the individual DC Comics shows needed.
History suggests the ratings increases will fade as soon as next week, but the one-time shot provided tangible gains to the season averages for “Supergirl,” “The Flash,” “Arrow” and “Legends of Tomorrow.”
All four shows hit or tied season highs in adults 18-49 and viewers with the crossover, based on the DC Comics “Invasion!” storyline from the late 1980s. All four also got above a 1.0, a rare accomplishment on The CW: The last time the network had four shows above that mark was the week of Jan. 27, 2014 (“The Originals,” “Supernatural,” “Arrow” and “The Vampire Diaries”).
“Supergirl” and “The Flash,” the network’s two top-rated shows, each drew 18-49 ratings about 36 percent above their prior average for the season (1.1 vs. 0.81 for “Supergirl,” 1.5 vs. 1.1 for “The Flash”). “Arrow” (1.3 vs. 0.67) and “Legends of Tomorrow” (1.2 vs. 0.62) had bigger gains, with each show nearly doubling its average.
Now, the bad news: Those ratings probably won’t last. Last season’s “Flash”-“Arrow” crossover gave a one-week boost to “Arrow,” but it returned to its average numbers the following week. The same thing happened when Barry Allen (Grant Gustin) visited “Supergirl” (then on CBS) in a one-way crossover last spring: “Supergirl” got a 31-percent bump that week, then gave it all back in its final two episodes of the season.
We can say with certainty that “Supergirl” won’t experience any crossover halo next week. It’s done until the new year, with repeats scheduled for Dec. 5. “The Flash,” “Arrow” and “Legends of Tomorrow” all have one more episode in 2016 before they go on hiatus until mid- to late January.
That’s not exactly a recipe for sustaining big numbers. But The CW will take the one-time bumps no matter what.
(This post has been updated with “Legends of Tomorrow’s” final ratings.)