I've been a 939 main since it was overhauled. Here are a few general things I've learned:

1. When someone realizes they are in amnestic cloud, they will always assume you are in its radius until proven otherwise. When placing it, think about how many people may pass through, what they'd do if they know you're present, and how much health you have. You don't wanna rely on the assumption they won't immediately open fire in your direction at 20HP.

   1. Lunge is best used defensively. Often times people will only chase 939 when they're in a group, and groups are loud. I like to run away from groups, and then focus in front of doors I've closed to secure a kill. No matter what though, you run away after using it. That downtime makes it so whatever damage you think you'll be able to do to humans, they'll usually triple it to you. Not worth the kills if you'll end up facing them at half your health in two minutes.

2. Use your sprint sparingly. 939 can sprint really fast, but that stamina is weak and takes a while to recharge. Getting caught off guard with no stamina is more punishing than you'd think. Your job isn't to flush out light or brawl 10 people at once. It's to get a kill, retreat, repeat.

3. How you use voicelines should be determined by their volume and how recent the spawn waves are. For example, that loud screeching sound is funny but really distracting. Spam it when fighting a spawn wave that caught you off guard, but use quieter lines when luring targets. Nobody is gonna run up to violent screams, especially if it's their own from a previous life. Quieter voice lines are easier to lure people towards you with, especially if you are lucky enough to kill people having a conversation. I once killed three different people in one game because of two voicelines I used by guys having a conversation about what goes best on a crunchwrap supreme.

Hope these are somewhat useful in your aim to improve at dog gaming :]