When does the evasion chance actually register?

[donnygamini]

My strategy lately has been to cloak after the enemy's first volley is fired, just after I see the missiles coming close to my ship. I'll also sometimes drop all power to the engine early, and load it up to full after a volley is fired if my cloak is still recharging.

Question is... does this make sense? It seems like the evasion chance changes instantaneously, but I'm not 100% sure.

[5thHorseman]

If you have shields, it triggers upon the shield pass, and you see it then. Cloaking after you see that won't affect if the missile hits or misses, it's already decided.

If you don't have shields, it triggers when it would hit the room.

In short, you can never know if your cloak will help dodge a missile that will otherwise hit, unless your dodge is 0% to start but if that's the case you've got other problems. Either the missile hasn't decided yet, or it already has and cloaking won't help.