MVP has nothing to do with kills, deaths, or assists, but with how much money you earned in total in 1 match.
To obtain this ProTag, you must earn the most money of all players on the winning team. ex: Player A earns $4000 but his team loses. Player B is the highest scorer on the winning team with $2000 plus the $1000 bonus for winning, giving him a total of $3000. In this scenario Player B is awarded match MVP even though he was not the highest earner.
This is an Achievement that gives you 20 .
It is also a ProTag that you can unlock for $30,000.