I would suggest coupling this with the 10 goal wonder achievement. Pick a national team, Brazil, Argentina, Italy or Spain. Spain is the best due to them having really good strikers. Then play against Nancy from the french league, a 2 1/2 star team, the lowest I could find in the game. Set the game to semi-pro and to the max half length, I believe its 20mins. In a 40 min game like this you should easily score around 15 goals, and if your good you can squeeze out 20+. two more matches like this and your set. You need a total of 200 goals over 50 games, so if you can pump out 50 or 60 goals in 3 games, you now only need to manage 3 a game. If you play a manager mode and feel your not scoring enough, you can always come back to this in the kick-off mode and pull in another couple of games. even if you are dead slow, and want to be real safe about it. if you can score 10 goals a game, do this 20 times and then just play the game regularly from there on in. Soon as you play your 50th game it will unlock.