I am going to try and combine all the useful information about this achievement into one guide.
The first point is that you can see how many games you've played offline on the home screen on the billboard. Unfortunately this number can be misleading as it includes games played without your pro, and also doesn't include online games, if you ever played before the servers went down. But it is a decent guide to how many games you've played. The other number of games played under profile manager also includes any online games.
The quickest way to get this achievement is by getting your pro sent off in every game you play of a be a player career. This still counts as a game played but doesn't take as long as the rest of the game simulates once you get sent off.
I've tried to break my ideas up into 15 rough steps:I
-Edit your Virtual Pro to be a goalkeeper and move him to Shamrock Rovers in the Irish League. Also make sure he is as young as possible (birth year 1994) as this delays your player's retirement.II
-Head to "My FIFA 11" in the main menu, then select "Edit Teams", "Squads", "Club Transfers", then go to Shamrock Rovers under Republic of Ireland and transfer all their goalkeepers to other teams, leaving your virtual pro as the only goalkeeperIII
-Then go back to the main menu, this time go to "My FIFA 11", "Edit Teams", "Players", "Create Player". You need to create a goalkeeper with all stats at 0 and minimum height. Put him on the Shamrock Rovers team.These steps so far have basically made it so that you can't be dropped from the Shamrock team. When you get sent off you miss a game, and the other goalkeeper will play in you place. We have made it so he is so bad that they will always want you back instead.IV
-Now from the main menu go to Career Mode and make a new career with Shamrock Rovers. Choose to be a player (NOT a player-manager) and put squads to current customised.The reason you can't be a player-manager is that when your pro is sent off, if you're just a player the game ends, if you're a PM you take over the whole team.V
-Pick to be your virtual pro.VI
-Once the new career is generated, in the career mode menu go to "settings" then save, and save the same career lots of times with different names. This means that when you have to eventually retire, you can just load another ready made save.VII
-Now you can start playing. Your aim in each game is to get sent off as quickly as possible, and to do this you should try and tackle opposing players from the back. Some people find it easiest to foul the other team's goalie. When you get sent off they'll bring on your created bad player.IX
-When you get sent off in league games you get a one match ban. So after each completed game, go to calendar and simulate until the match after the next one, simming through the game you're suspended for.X
-While you wait for it to sim you can do something interesting, such as writing achievement guides that no one will read like this one (so meta)XI
-At the end of each season, stay at Shamrock Rovers.XII
-I find it takes maybe 2 to 5 minutes from getting one game done to getting the next done (including time in game and time in menus/between games). 2 minutes is a best case scenario and that will be if you mash the a button to skip through menus and replays.XIII
-Suppose you get games done in 2 minutes, well then 2 mins times 500 games equals 1000 minutes total, 1000/60=16.66666 hours. This is the best case scenario for the achievement, it is very likely that it will take longer.XIV
-Overall this is a horrible achievement that takes ages. The process is pretty dull, so I recommend you listen to the radio or to music whilst you do this to ease things along. Good luck and I hope that someone found this guide usefulXV
-I got this achievement when the counter on the main menu said 532 games played, and the one in profile manager 558. The achievement unlocked just after the game ended (and it unlocked from a game in which I was sent off).
p.s. My advice for FIFA 11 achievement hunting for new players: I would personally first try to get the glitch to work (this is now the only way to get the online achievements), with your virtual pro in the team as the keeper. See guide the guide for how to do the glitch here
and also see this thread
Trying for the glitch has the bonus of racking up pro games, albeit at a fairly slow rate.
Then after you get that glitch to work and get the online achievements (it takes a while, keep at it), I would start doing this 500 game process. You'll probably get a good number of miscellaneous achievements along the way, and you can always round up the last few after you get this one to finally complete the game