I noticed several of my recent games were won by the runner stealing agendas from R&D (the corp player’s deck).
The corp has to spread his ICE across several servers, and in trying to protect a remote server often can’t help leaving R&D under-ICEed. Even if it cost a few credits to run past a couple of ICE into R&D, it seems always profitable for the runner to do so.
So how profitable? We need to look at the distribution of the agendas in the deck.
A netrunner deck is at least 45 cards (although this depends on the stats on the identity card). You are allowed to have more, but not less. Typically you do not want to have more than the minimum number of cards in your deck because this just dilutes your strategy, making it less likely that you will find the cards you need.
The pre-constructed corp decks in the core set have 49 cards.
The rules say you must have 20 or 21 points of agendas in a deck of this size. Typically, this is three 3-point agendas and six 2-point agendas (21 points). This gives a total of 9 agenda cards.
So you would expect to draw an agenda 1 in every 5 or so cards. Is a one in five chance worth it?
Well, normally you can only access one R&D card a turn no matter how many runs, since you replace the card after accessing it. If however you can trash that card, then running again will access another card. Using any effects which allow you to access more cards helps as well.
But let’s consider the simple case of accessing one R&D card per run.
You need 7 points to win the game. Each agenda is worth on average 21 / 9 = 2.33 points.
You would expect to access an agenda 9 out of 49 accesses, which is 18% of the time.
So each run against R&D will return an average of 18% of 2.33, which is 2.33 * 0.18 = 0.43 agenda points.
If you get 0.43 points on average per run, how many runs do you have to make to get to 7?
This is 7 / 0.43 = 16 runs.
Another way of looking at it is that on average you need 3 agendas to win. If you get an agenda 9 out of 49 runs, then you need 3 * (49/9) = 16 runs.
For just 1 agenda, it is about 5 1/2 runs.
So you can work on the assumption that if you spend 5 or 6 turns during the game running against R&D, you should manage to steal at least one agenda. Not a bad thing to do if nothing much else is going on, or if you can sneak in early before the corp player can get his ICE installed.
There are other advantages to running against R&D even if you don’t hit an agenda. You get to see what the corp player is going to draw next. Over a few turns, you will know pretty much what they have in hand. In particular, you will know that they haven’t drawn any agendas!
You can sometimes trash a card. This can remove an annoying asset or upgrade, and also allow you to squeeze in another run on R&D that turn. Most corp decks have around 10-12 assets or upgrades, so if the card you access isn’t an agenda then it is about 25% likely to be able to trashable.
There are combos possible with cards from some of the expansion packs that can really mess with R&D, stealing agendas before the corp can ever draw them. When I get to deck-building, I might try them out.