I'm fairly certain 1997 was the league's first year of 4.6 because Settles didn't have the accuracy to throw the ball and I spent most of the year testing new runs on the engine while waiting for him to develop.

I'm looking to scrape ALL of our 4.6 regular and postseason games which is why I'm asking

Definitely 1997, my HOF QB went from averaging near 5000 yards & 48 TD passes to 3400 & 17 in 1997.