(adsbygoogle = window.adsbygoogle || []).push({}); I found out that you need to play zombies 5 days in a row.
So, basically, you will get 1 tally mark every match.
Let's say you got the 2 shotguns without the blue eyes. Play 5 days in a row, well, it depends on what tally mark you are on. If you are on the 3rd tally mark, you just have to play 2-3 days in a row.
So, just play 1 match each day, and you will receive 1 tally mark.

Sorry for my bad english...