Not accusing you of anything, just saying it's impossible to calculate. Bigger ships are easier to hit in group engagements, while smaller ships and ships with faster turning are harder to hit. In one on one engagements size plays less of an importance, and ability to strafe and aim becomes more important. In a skill-based game you simply cannot apply maths to these situations. There are too many factors to consider and skill is not a measurable quantity.
Your shield may fail you miserably, but in large group engagements mine goes largely untouched. That is something you can't put a number on.