You need to go to "Game Theory" to tell if the 60% rate is "good enough" or not. And, for the record... I don't know the answer.... but I do know just enough to be dangerous.
It goes something like this. Assume you are a Dangerous Organization (DO) and the DO wants to smuggle a Dangerous Thing (DT) onto a plane. But, it's not just getting the DT onto the plane - it also has to be used effectively.
And considerable resources are spent training people to use the DT. And those people are supported by other people during the recruitment and training. The DO has between 6 and 20 people in that cell, perhaps?
Now it's time to smuggle the DT onto the plane. Assume there is a 50/50 chance of getting the DT past security. If your operative gets caught there is a chance that others may be implicated, even if you have been careful to cover the support team's tracks.
All through the training period there is a chance of the support team being caught as well.
So - is 50/50 odds good enough to make the operation worth it? Probably not. So, you add a 2nd operative. You only need one of them to be successful for the entire operation to be successful. If I understand my stats (and don't assume that I do) then there is a 25% chance of complete failure - where both operatives are caught. Is
that good enough odds to make the whole thing worthwhile? Will someone in the DO think it's too dangerous and make a deal with the authorities.
What about 3 operatives. Now the chances of one successful attack go way way up. There is only one chance of complete failure - all 3 caught. But chances of success are either 3x3 or 3x3x3 (stats, eh?).
What about 4 operatives? Still just one chance of complete failure - all 4 caught, but having at least one operative get through is much much higher.
Or is it?
How many operatives can be caught before the the authorities realized that there is an attack happening, and step up the scrutiny? If you have just 2 operatives then having one get caught probably won't trigger a huge crackdown (but we've seen in the past that it does trigger heightened security process).
But if two operatives are caught (out of a hypothetical three operatives) then the timing matters. Did the 1st operative get through, and so it doesn't matter if the 2nd and 3rd operatives are caught - or did the 1st two operatives get caught and now the 3rd is walking into a net? What if the 1st operative is caught - what is the 2nd one thinking, and then the 3rd?
It gets very complex.... and you can be sure that DHS has gamed all this. The've calculated how good "good enough" is. There is no way to get 100% perfect screening. There is only "good enough" for the money the've been budgeted. So, you'd better hope that their "Gaming Theory" assumptions are good, eh?
