X-wing with an Engine Upgrade charging an enemy ship head on. It moves second and ends up at Range 2, a base's distance out of Range 1.

Should it boost or focus?

I remember the mathematical discussions on Expose, and the most damning thing was that even if Expose weren't four points and an agility penalty it would still be worse than the generic focus in terms of buffing your damage. So I wondered, does the same logic apply here? When is it best for the X-wing to close in and when is it best for it to Focus on the Range 2 shot?

Yup, end result is, if you're rolling 3 dice focus (or TL) is better than just adding a die. If you use R7-T1 and boost and TL, then you're in much better shape.

I would say, only if your chances of killing the defender were high, as you will now be giving the surviving ship the +1 attack die as well.

Mathematically speaking you take the focus every single time unless it's clear you can't grind out the game and need to take some risks in the hope they pay off!

Three dice with a focus or target lock are generally better than four unmodified dice - that's what the debates about expose are about.

Also, not boosting in close means that incoming return fire won't be getting a bonus die either.

The times you should be looking at trying to close the range with a manouvre action rather than taking a token are:

1. You're moving in under the range of an enemy secondary weapon like a torpedo, or outrider-mounted heavy laser cannon
2. You have a special ability which triggers when at range 1 (mauler mithel and winged gundark spring to mind)
3. Your opponent has a special ability which triggers at range 2 (tactician or chiraneau)
4. Closing in will avoid the arc of fire of a third ship
5. Closing in will put you in a better position to manouvre next round (a stressed heavy fighter like a BTL-A4 that won't be able to turn to shoot back if you tuck in behind it)

depends on how it sets up your maneuver for next turn

I could see it also depending on (a) pilot skills, to see who's shooting first, (b) the remaining health on your ship versus your opponent's ship, © the attack dice your opponent's got, etc, etc, etc. Boosting to range 1 doesn't just give you +1 die, it also gives it to your opponent, so lots of stuff about your opponent should come into play when making the decision, too...

...to say nothing of "what will I do next turn if I boost, versus if I don't?"