this is my first solution i have written, sorry if its not super great.
after many many many hours of online play with all match types, and using an excel spreadsheet to track wins/loses and total matches played for each game type.
this achievement seems to only include ranked and player matches <1vs1 private counts>
private koth and private survivor did not seem to count.
one other issue is the achievement pop.
this one does not give the satisfying "pop" sound or on screen notice.
this is very frustrating after many many hours of grinding just to have no gratification.
hope this helps those out there, still grinding away.
find a friend, win 100 and loose 100 and both get this and the "over the top!" play 200 matches achievement :)