STREET FIGHTER X TEKKEN

Select versus mode
Connect the second control
Put seven rounds
When choosing the character of the first places you 100% control of life, and the character of the second control you put 0% life
So by the time you attack him, he will die in hour
you will get perfect 4 per game in 25 matches then you already get the achievement.

I recorded a video when there was perfect for my four wins, so if anyone has any doubts still only see the video.

If you're having trouble against the CPU or human opponents online, you can set up a VS match with a 2nd controller and just go to town on the inactive controllers characters. Easy way to win by perfection as well as adding to your launcher, cross art, ex super move, etc totals

The following is the method I used to obtain this achievement, performed via Xbox 360 Pad:

Game Mode: Versus
Controllers Required: 1
No. of Rounds: 7
Time: Infinite
Difficulty: Easiest
Scramble Battle: Off
Fighters: King and Marduk vs Ryu and Ken
Handicap: King and Marduk (100%) Ryu and Ken (0%)
Time Taken to obtain achievement: Roughly 30-45 minutes

Why should I choose these settings? - Now the second fighters don't really matter as you will only be using the first character selected, in my method I was King. Now the reason why you should choose the Easiest difficulty is because the other team will not usually jump when the fight starts (however at random times there will be the odd jump performed by the computer). You should choose 7 rounds because this will mean that you will score 4 Perfects for fight, this will result in a total of 25 fights to obtain 100 Perfects. Once one fight is completed choose Rematch in order to quickly rack up Perfect rounds. Finally the infinite time limit, this doesn't really matter as the fight will only last a second, but if the opponent hits you this is so they can defeat you in order to win the next round.

The controls/move to use: With King the attack I used was performed by holding the D-Pad (Xbox Pad) Up and to the Right (the same direction applies to the Arcade Joysticks) whilst holding the D-Pad to the Up Diagonal Right direction I would press the LB button (the combination for a Light, Medium and Heavy Punch attack). This would make King performing a kind of diving punch attack. Hopefully the attack will land and you will score the perfect. Sometimes you may jump over the opponent, or the move won't connect with the opponent, not a problem if this were to happen simply press LB again and King will push his chest out in order to hit the opponent.

THE OPPONENT HIT ME NOW I HAVE TO RESTART!! - Yes, chances are at random times the computer will hit you. Keep in mind you need to score a Perfect ROUND, not match, so simply don't touch any controls and just let the computer win the round and then you win the next round.

If you read this rather LOOOONG and detailed solution THANK YOU! and hopefully if you did this exact method, you too should obtain the achievement in the same sort of time as I did.