When I said 5 * 7.4% I was referring to the fact that you could have 5 fleets of 100 cruisers or 1 fleet of 500. Thus in a single turn you could have 5 attempts at the 7.4% chance. While each one taken on its own is 7.4%, the chance that 1 in the 5 is successful is not 7.4%, I just forget what it is. Again if you flip a coin 50 times, the chance that in any 1 flip you get tails is 50%, but what is the chance that at least 1 time in the 50 you get tails?
Anyway just an update, out of 65 assaults that I am currently running, 5 were defended, 1 was successful. The successful one was from one lone scout, go scout.
I don't remember those rules, which we learned pretty early on. Logic would say that if an event has 1% odds of resulting in something, doing it twice would double the odds of it happening at least once. However, it's obvious that if you do it 100 times, it's not 100% guaranteed to happen.
Indeed, if you flip two coins, you have 75% odds of having at least 1 heads (only 1 in the 4 possible combinations doesn't involve heads). Mathematically speaking, though, I'm not sure what the formula is.
