re: What is going to take to stop the fans from charging on to the court or field?

Put an amount of time on the scoreboard that allows the opposing team time to exit. If fans come before then you penalize the hell out of the home team. Loss of home games, loss of post season play, vacate the W, lose fans inside the stadium/arena for an amount of time, etc.

You’ve got to protect the players/coaches but also allow the excitement and passion that comes with college sports. It obviously doesn’t happen at Bama, but it is pretty cool to see it happen at annual door mats who pull the big upset.