NFL Blitz

this is achieved in the single player Blitz Battles. when you go in there, you have to make a team name. think of something unique, as you cant use the same name as someone else. after that, just start playing games. winning earns you leaderboard points, while losing will subtract points. this is also a good way to earn blitz bucks for the store and the elite league, but for this achievement you need to focus on the leaderboard points. im not entirely sure what the formula is for how many points you get, but from what ive seen, the winner usually gets about 6500 points, while the loser loses about 4000 points. you start on the LOCAL battleboard, relative to the state you pick as your home state. the board will only show 25 players (including yourself), and you have to earn enough points to reach the top of the board. after that, you play a rank up game to move on to the next board. there are 4 boards in the local section leaderboards. you start on ROOKIE, the move to VETERAN, PRO, and finally ELITE. after you rank up past ELITE, you move to the REGIONAL battleboard. you have to repeat all of those steps to rank up through the 4 boards of the REGIONAL section. the achievement will unlock upon graduating from the PRO board to the ELITE board.
note: you can never have negative points. so if you start off really badly and lose youre first 10 games like i did, you will never be lower than ZERO points. once you get some skill, you can start winning and get your points lie a seasoned veteran.
also keep in mind that quitting early, or your opponent quitting does NOT affect the number of points you receive, though quitting DOES mean you lose the game. one player quitting WILL result in far less Blitz Bucks though.