It’s impossible to know what it would have been like for Tom Brady to throw passes to Lynn Swann, Barry Sanders to take handoffs from Patrick Mahomes, or just how much a defense with Warren Sapp, Luke Kuechly and Deion Sanders would have stifled offenses across the NFL. But you can’t blame imaginative sports fans for trying.

Consider Nick Baumeyer one of them. Inspired by a Discord conversation with friends about what an all-time NFL roster could look like, he endeavored to create a game for sports fans to put their knowledge to the test. In June, Baumeyer launched 20-0, an online game that lets players draft a fantasy team from varying eras in gridiron history in hopes of amassing a score worthy of a perfect season.

The game found an audience immediately, garnering roughly 280,000 unique visitors and 1 million plays during its first day online after Baumeyer merely posted about it a few times on X. In 10 weeks or so, those figures have grown to around 2.2 million and 30 million, respectively, and daily website traffic currently sits around 65,000 to 70,000 users.

That’s created a lucrative side hustle for the 27-year-old Baumeyer, a software engineer by day at an AI legal tech company. His endeavor has generated just over $250,000 in revenue thus far, and it’s almost entirely profit. Baumeyer bootstrapped the business with less than $50,000, and his only expenses are server costs, which he’s reduced to about $2,000 per month, and some design and public relations work that he contracted out for.