I'm almost done with this and I might leave it as it is.
The year is 1965. The NFL has 2 divisions, East and West. Each division has 7 teams. The season has 14 weeks. The general rule is each team in each division plays the other teams in its division twice and plays two games against the other division. So right now I have it working, but sometimes the non divisional games repeat. That is, a west division team could play an eastern division team twice during the season. I can fix this, but I don't feel like it right now, lol. I'd have to create a master list of the interdivisional teams and check insertion of a game against existing game matchups. I'm already doing something like that for the other games so.... Also, I had to build in a failsafe so if the code locks up because it can't satisfy the schedule rules, it will abort the scheduling and restart. That was actually easy to do.
As I'm not a professional I have a bunch of bad habits. One of those bad habits is that I keep trying to code something using an algorithm I made up in my head that is at times essentially a square peg trying to fit in a round hole. I had to step back a couple of times and write out the facts and the pseudo code of what I was trying to do and in doing so I found some glaring omissions in my code that if it had teeth would have bit me.

Sometimes I get ideas, but I don't think them through starting from step 1.
Any way here's a short textmode demo of a season schedule that was generated and then a screen of each team's "buckets" that show how many times they played an opponent.
https://www.youtube.com/watch?v=TpK-ROP4z-8My next step for my Retro football is to have the user select a favorite team (maybe), then generate the schedule, have a schedule screen to select which games to simulate and which to play. Then to sim the games without trigging the graphics and then play whatever games in the selected week aren't simulated. I also have to put in the ability to save the state of the season and reload it from file, or restart a new season. I also have to build in the retention of who won and lost, the team standings (and a display standings screen) and the stats for each team (and a screen for reviewing team stats).
AND I'd like to have NFL football helmet icons to select games with and to display somewhere while a game is being played (not "simmed").