Okay, so this will not be news to anyone, but this achievement really does suck, due in part to users quitting, and the match being recorded on EA sports, but not towards the achievement. I'm currently on 156 matches, and no achievement. With no indication (without recording separately) as to how many were full, finished matches. Very annoying. 

Took me about 170 matches yes that means almost 1 in every 2 matches my opponent quit. I am thinking the 50 hours on the pitch secret achievement will take 1000 matches :p

Finally worked it out - i went offline and my total completed matches is 152 (on the game itself), and looked at my non-online matches info, which stated i have completed 75. So, subtract these from the 152 = 77 online matches completed. Just 23 more to go.

I always felt the achievements for janky for that game. 

how did you check your non online games?

i got to 196 played games..toward the end i just pick shitty teams and get red carded out to get it to save since everytime i am up by 2 goals they quit so i just lost a bunch of rank points but who cares i finally got 100% done with fifa