Do detection percentages on simultaneous node hacks stack?
I only recently learned that you can hack nodes simultaneously and have yet to test this out properly.
Before you are detected and the countdown begins, does hacking two or more nodes simultaneously stack their detection chances? E.g. If I hack two nodes that have a 45% detection chance at the same time:
- Does that bump it up to a near-certain 90%?
- Does it increase it by some other amount to make it more likely but not so difficult?
- Does it remain at the highest individual rating (45% here)?
It would make pre-detection hacking necessarily slower and more careful if they do stack...
Solution 1:
No, the detection rate does not change the more nodes you attempt to hack at once. They will still have their own individual chances. Just note that fortifying a node at a given level generally has a higher detection rate than initially capturing a node at the same level.
So if you know that you are going to be detected with certainty (or very high probability) and you're out of nukes or stops and you have a choice of nodes, I'd suggest doing this as quickly as possible (in order of highest priority):
- Fortify the highest level nodes first (preferring the nodes en route to your IO node). (will usually be the slowest)
- Fortify the node you're on.
- Capture nodes leading toward the "exits".
Chances are, the trace will begin when one of them completes but you'll be in good shape since you have a lot of nodes fortified already.
Solution 2:
In terms of probabilities, hacking nodes simultaneously is exactly the same as hacking them concurrently: each node has an independent chance of detecting you, so the probabilities multiply. Your second bullet point is closest, although treating the two hacks as one event isn't really the right way of looking at it.
To follow your example, the chance of being detected when hacking two 45% nodes is 1 - ((1 - 0.45) * (1 - 0.45)) = roughly 0.70 (70%).
The advantages to hacking simultaneously are:
- it's quicker overall
- if the first node to complete results in detection, the second node is already started, so you get a relative headstart on the trace.