To finish off this tough winter quarter of work, I had to finish my Visual Essay series covering "10 Things That Changed the Game."

The first of 3 in this series illustrates the change from using natural grass fields in the NFL to using astroturf. Astroturf seemed great because with grass everything got sloppy and muddy, but astroturf caused more injuries due to the lack of cushioning and also the heat that would come off the turf. It was basically like playing on cement which is why I'm showing a man painting the "grass" on top of cement. This use of turf started in Houston at the Astrodome (hence the term "astroturf"), so I showed the iconic roof of the Astrodome, along with having the painter's hat with the Houston Oilers logo on it.

The 2nd of 3 in this series illustrates the use of Instant Replay in the NFL.  It was such a great change, because now if there's a terrible call that could effect the outcome of a game, the play can be looked at by the head ref and overturned if enough visual evidence is displayed by the replay.

The 3rd of 3 in this series illustrates the 2nd biggest thing to change the game...free agency. Before free agency, when a player entered the league, whatever team picked him up would basically have ownership over that player until they retired. Free agency allowed the players to have some say in where they play. One of the biggest free agency pick ups in NFL history was the Green Bay Packers picking up Reggie White from the Philadelphia Eagles. Reggie White was a larger than life defensive player that was considered by the sports nation to be the greatest player in Philadelphia Eagles' franchise history.