Its worth noting that Opportunist always triggers on snap shot before the enemy ship can perform actions. Therefore, Opportunist will always trigger on that first roll.
Opportunist gives you 0.5 damage, on average (naked roll of 1 more die) and gives you a stress token. 4 points.
Juke gives you either 0 or 1 extra damage (0 if the opponent rolls no evades, 1 if they do) and requires an evade token. 2 points.
Crack Shot will almost certainly give you 1 extra damage once in the game, and requires nothing more than a target.. 1 point.
I prefer Snap Shot + Crack Shot overall. Its a 20 point build on Green Squadron Pilots, so you could fly 3 with a small-based ace, or 2 with a large-based ace, or a true swarm of 5.
So building on this, is the difference in average effectiveness something along the lines of:
Oppertunist is better against low agility ships (0-1) where the expected extra damage output (0.5) exceeds the expected damage mitigation of the defender (0 for AG0 and 3.75 for AG1)
Snapshot/Juke is better for agaility 2+ ships where the cancellation of defenders expected mitigation (0.75 for AG2) exceeds the damage output forgone by not taking opperunist (0.5) [i.e an AG 2 defender has expected number of evades of .75 against the a-wings 1 hit, juke/ crackshot then cancels this).
Obviously there are the other considerations such as points, taking stress vs needing to take evade vs 1 use only to consider. For me juke comes out on top in my build but I can see crackshot being good as well.
Edited by asters89