It definitely seems to be pretty random, I’ve seen them triggered after huge games and after performances that make you go huh? In my online league I use the Eagles and had been trying to build up JJ Arcega-Whiteside. His rookie year I had a couple of big games with him but didn’t have a huge year since I had DeSean Jackson, Alshon Jeffery, Ertz. His second season though I had something like 84 catches and 1300 yards with a good amount of tds and didn’t trigger a single breakout. Even after several 100+ yard and multiple td games I couldn’t get a breakout to get him to superstar. But after a game where I posted something like a 5/65/1 stat line with Nelson Agholor he gets a breakout. After drafting a star dev WR in the 1st round the following season I was also able to get a breakout for him within a few games of his rookie season to get him to superstar. I have since given up on the Arcega-Whiteside experiment and traded him to another team since I don’t have enough targets to go around with how many weapons I have.
I also had a similar experience trying to get a breakout to get Miles Sanders to superstar. I had something like 6 or 7 weeks in a row with 100+ yards and multiple tds and didn’t trigger a single breakout. During that span I watched another user in the league get a breakout for their RB literally after a 5 carry for 8 yards and 1 td performance. It wasn’t until the end of that season after yet another huge performance with multiple tds that I finally got the superstar breakout opportunity for Sanders.
As frustrating as it can be that its seemingly pretty random, it’s a good thing that it is. The way breakouts were handled already promotes force feeding as it is. If the system to determine breakouts was purely stat based it would be a nightmare in online leagues. Plus without it being random it would tend to favor the top teams in the league which just keeps helping the rich get richer instead of promoting the parity you see in the NFL. Although even being seemingly random it does seem to favor certain teams, usually playoff teams in my experience as we have a few teams that have gotten far more breakout opportunities than others. Heck there are a couple of teams that have literally gotten 3 breakout opportunities in 1 game while I’ve only had something like 4-5 the entire cycle.