The CW is home to five Arrow.

Arrow premiered in 2012 and became an astounding hit for the network, which is why they pursued Black Lightning, isn't part of the Arrowverse, it's still based on a DC Comics property. So, to avoid oversaturation, and to prevent cannibalization of their other comic book properties, the network chooses to air only four superhero shows at any given time.

Related: The CW: No Plans For More DC TV Shows For Now

The CW president Mark Pedowitz told Bloomberg that, due to increasing competition from comic book-based TV shows, they will only air four superhero shows at one time, whether they are part of the Arrowverse or not. That doesn't mean he expects the superhero TV renaissance to fade away, though. He said: “The audience will tell you when the fatigue has set in. If you have a quality show or a fun show, the audience will stay with it.”

So far, the decision to air only four superhero shows seems to have primarily impacted Supergirl and Legends of Tomorrow, which are now sharing the same time slot. Legends of Tomorrow is currently on hiatus, but it will take over Supergirl's Monday night slot in mid-February when the Girl of Steel's series goes on break.

It's worth noting that while The CW has six live-action DC Comics TV shows on the air (and seven total comic book-themed programs, including Riverdale), they also air Constantine and Vixen on CW Seed, thus bringing their total DC Comics content to eight shows. However, only five are superhero-related programs: Arrow, Flash, Supergirl, Legends of Tomorrow, and Black Lightning.

That's a large number for one network. In fact, with all those programs under its belt, The CW has the most comic book-themed content of any network or service - on broadcast, cable, or streaming. But in order to avoid being labeled as a superhero network, they air other programs as well and restrict the number of DC superhero shows airing concurrently to just four.

More: Why The CW Needs To Cancel Arrow

Source: Bloomberg