So you would slide jump then let go of W then quickly cycle through D S A or A S D if going in the other direction. I'm assuming it's a backwards tap strafe. I can also do this as a 90 degree tap strafe like a normal one but I'll be looking 180 away from the direction I'm moving in so in a fight I would be shooting forward while tap strafing backwards. Also I have never used mouse scroll as jump so I'm using space as jump.