Originally by: Max Warg
Because you get a rate of fire incresse with a explosion radius penalty (smaller explosion). So higher rate of fire with a little less damage.
Sorry, but you have it completely wrong here. Let me give an example:
Rocket explosion radius: 20m
Light missile explosion radius: 50m
Bane torpedo radius: 400m
Raptor sig radius: 34m
Kestrel sig radius: 47m
Raven sig radius: 460m
The gist of it is, you want the lowest explosion radius possible. It's not intuitive, but it is how CCP implemented it. If the explosion radius of your missile is less than the sig radius of the ship you are shooting at, the missile will do full damage (ignoring the ship velocity). If the explosion radius of your missile is greater than the sig radius of the ship you are shooting at, there is some damage reduction.
In the above example, rockets will do full damage to all 3 ships, light missiles will only do full damage to the Raven, and torpedoes will only do full damage to the Raven as well. If a ship has a sig radius of 40m and gets hit with a torpedo with an explosion radius of 400m, the damage is reduced to 10% of the full torpedo damage.
This is where rigs that increase precision come in. You use rigs that decrease explosion radius to do more damge to smaller targets.
Explosion velocity comes in where ships are moving very quickly. I recall orbiting a Raven in my Crow at 7km/s. The explosion velocity of torpedoes is 250m/s. The Raven's torpedoes were hitting me for 0.0 damage because my Crow is moving so quickly, even though the MWD increases the sig radius of my crow up to 150m.
Refer to the tracking and missile guides here:TrackingMissiles
And, a shameless plug for Agony Unleashed's PvP school:www.agony-unleashed.com