The King of Fighters XII

For this achievement you have to win 100 matches in Online Mode. In order for the wins to count towards the achievement they must be in either the Online Arcade or Online Ranked. Player matches do not count. You are most likely gonna to need to boost this, there are very few people that play this game online still. I hope helps.

Let Me start forst and foremost by stating that the online for this game is dead (and has been so for quite sometime).
1. GRAB A BOOSTING PARTNER - preferibly someone who is willing to leave their xbox on overnight and also owns a turbo controller so you can sleep through this grind. (they cost $20 bucks at gamestop)
***if you dont own a turbo controller you'll have to rely on playing the matches out, so my suggestion would be for you and your boosting partner to break this up into sessions to make it less of a pain.
2. -set up a 2-player online arcade lobby
-Both you and your friend set you're controllers to turbo the button
-sit something on the button so that it stays pressed down
-go to sleep
-when you wake up, you will have played around 100 matches depending on when you started and finished.

***player matches DO NOT count

*** While going for this achievement, you and your friend can also go for the following achs:
"Warrior" (win 5 battles)
"Gladiator" (win 25 battles)
"Hero" (win 50 battles)
***UPDATE - Acedawg4 has confirmed player matches DO count towards this achievement.
Use 2 player winner stays, this should take you less time than my method (2 min a match even with draws). Thank u Acedawg4 !!!!!!