I too use an MX518. While I don't play competitive really, I like to think I could. For me it's mostly about prediction. Which is guided by experience and memorization.
I try to set myself up in similar locations and watch what the s…
Level 2 weapons, shotguns, 2 marines vs fade, fade should have some fear (since latest SG buff). The obvious solution is the less skill the marine players have, the bigger groups you should move around in.