Why 3 years. In my opinion, players and passing games are way more advanced than in the past. Kids are throwing over 1000 times before they get to college. In college, they're throwing another 1600 times. 15 years ago, this wasn't the case, plus most of the college passing concepts are in the pro's which wasn't the case years back. Its like the nba vs the international game. You see international players transitioning easier and quicker with success in the nba because the style of play is on equal footing. Lamar Jackson threw the ball 1086 times in 3 years, Peyton threw the ball 1300 times in 4 years. Qbs are coming in more pro ready than earlier generations.