I haven’t tried to play Atman in the current environment, but played it a lot back in the day and I suspect the basics are somewhat similar.
-Number one is that you want to get Datasucker on the table as soon as possible and start charging it. Strongly consider using an SMC for Datasucker if you don’t see it early; your Atmans are very easy to keep out if you don’t have Sucker.
-It’s hard for you to break ICE early on without ruining your economy. The install cost of Atman is its biggest drawback, and a good corp will exploit that. Consider Stimhack for fast econ that will get you free Atmans mid-run.
-Generally you want your first Atman to be Atman 0, both because it’s cheap and because it can technically break anything if you get enough Sucker counters. That said, the best approach is to install Atman mid-run with SMC/Clone Chip/etc and set it to whatever you need right now.
-A difference of 2-strength between Atmans is ideal as it means you only need one sucker to theoretically break anything. The combination used to be 0,2,4, but that probably won’t work for today’s meta. I suspect 3/5/(0) is probably best against CtM - the 0 is in brackets because you can substitute Inti instead against common ICE suites.
-Your endgame is cheap runs on R&D with 1+ R&D Interfaces installed - your rig is super-efficient when set up. Remote lock isn’t your strength because the corp can create scoring windows with timely Datasucker purges.
-Squeeze a single Parasite in if you can; removing awkward strength ice really helps smooth the whole thing out.
I find when using Atmans that random accesses hold a lot more value. Seeing a couple pieces of ICE early on before they are installed can be game-winning, especially if your opponent doesn’t know you are running Atmans as your main breaker suite.
That said, there are some “standard” values to choose for Atmans, namely 0 and 4. There are a lot of reasons for these values, and I’m sure I will miss some, but here’s the nutshell version:
A lot of popular and inconvenient/horrible ICE is STR 4 or 5. This includes Eli, Lotus Field, Ichi, Tollbooth, and Assassin. An Atman 4 and a Datasucker token or two handle servers stacked with these with relative ease.
Gearcheck ICE (at or around STR 0) falls easily to a couple sucker counters and Atman 0. This also includes Trap ICE, which while not popular is typically obnoxious. Preventing a Special Offer from firing can be game-winning if you can keep the corp in the hole for another turn or two.
So this has less to do with Atman itself, but a lot to do with the success of the former Katman decks. One of the single most important cards in the old Katman decks was actually Parasite. Parasite allowed you to disintegrate those problem ICE that Atman had a hard time chewing thorough. Really, your primary breaker was often Parasite (with Datasucker support), with Atman to walk through the conveniently strengthed ICE.
In the long long ago, the before time, the general plan was to setup a couple of datasuckers, a 0man, a 2man, and a 4man, roughly in that order, with lots of parasite support along the way and an RDI or two squeezed in wherever you could afford it. As with all things in Netrunner, though, this general plan required plenty of flexibility based on the board state.
This was all in an era where runners didn’t need nearly so much economy, though (when assets we basically a joke, and you really just had to trash ash and the occasional sansan - remember, whizzard was long viewed as the worst runner), and no MWL meant Kate was generally packing at least two parasites. I’m not sure this is at all viable in the current meta.
I wasn’t even playing netrunner when this archetype was popular, but I’d guess part of the problem with it now would be cards like Turing and Wraparound, more often thought of as anti-faust or eater, but certainly annoying for Atman as well. Wraparound requires a ton of suckers to beat, or an awkwardly high Atman, and Turing can’t be broken at all, and doesn’t die so easily to parasite unless on a central. Would this deck run an inti and a cycy to cover these, or just try to wing it?
Also, Cyberdex Virus suite exists now and probably does a certain amount of damage to decks relying heavily on datasuckers.
Maybe this would be better whenever glacier becomes popular again, but it strikes me as an awkward rig.
played against a katman nexus deck that kicked my ass a few weeks ago. katman and suckers deal with most ice while nexus skips annoying ice(like my swordsman). frees up the influence for 3 nexus in the deck too rather than importing breakers