I've seen this scenario posited as a Modern version of the Legacy Four Horsemen deck, only with the alteration that because of how it works, it can't be considered slow play, but I've also heard the argument that it is slow play anyway:

Anna and Noel are playing Modern. Anna controls Intruder Alarm and Goblin Test Pilot, and enchants the Pilot with Splinter Twin. After making a copy of the Pilot and resolving Intruder Alarm's trigger, she proposes the following sequence:

1. She will activate the copy of Goblin Test Pilot.
2. If the target is Noel or one of his creatures, she will let the ability resolve and move to step 3. If the target is herself or one of her creatures, she will hold priority and move to step 3.
3. She will make a new copy of Goblin Test Pilot and let the Intruder Alarm trigger resolve. She will then repeat steps 1 and 2 for each token copy of Goblin Test Pilot, moving to step 3 only once all are tapped.

In this way she will, probabilistically, target Noel with enough Pilot activations that his life total will become 0 regardless of where it started when this sequence began.

I've heard the claim that this is not slow play because the visible game state is constantly changing: abilities are being added to the stack and sometimes resolving, making token copies of creatures, untapping creatures, causing life total changes and marking damage on creatures, permanents are being tapped and untapped, and the stack is changing regularly as she keeps responding to Test Pilot activations that target objects she doesn't want to damage. The visible game state is never returning to where it was at an earlier point in the loop.

But then I've heard the claim that it is slow play because from Noel's perspective, Anna can go through many iterations of steps 1-3 without ever damaging Noel or one of his permanents, only adding more undesirable activations to the stack, which becomes increasingly more likely as she makes more copies of Goblin Test Pilot. If Noel has no responses, for him nothing relevant has changed about the game state if all Anna is doing is not letting those activations resolve by constantly holding priority. For Noel, there's no difference between a stack with five Pilot activations targeting Anna and six targeting Anna so long as she's not letting any of them resolve.

So is this slow play?

Per the IPG:
“It is also slow play if a player continues to execute a loop without being able to provide an exact number of
iterations and the expected resulting game state.”

This loop, by the definitions laid out in the IPG, would in fact be slow play. Unless Anna can tell us the exact board state that the game will end in when Noel is at 0 or less life total, which I think the chances of that are nigh impossible, then it is slow play.

Because it can't be executed as a loop Anna will have to play out each of these interactions. And personally, after 2-3 iterations of this, I would tell her she needs to make a different play to advance the game state.

Originally posted by Elliot Garner:

Because it can't be executed as a loop Anna will have to play out each of these interactions. And personally, after 2-3 iterations of this, I would tell her she needs to make a different play to advance the game state.

Is adding creatures to the battlefield, putting abilities on the stack, and dealing damage to your opponents not advancing the game state?

I suppose that it is advancing the game state. But in reference to the 4 horsemen in legacy, isnt putting cards into the graveyard advancing the gamestate?

Originally posted by Chuck Pierce:

Elliot Garner
Because it can't be executed as a loop Anna will have to play out each of these interactions. And personally, after 2-3 iterations of this, I would tell her she needs to make a different play to advance the game state.

Is adding creatures to the battlefield, putting abilities on the stack, and dealing damage to your opponents not advancing the game state?

Its not just that they are advancing the game state, its they must be able to determine the outcome of their loop. For example Adrian shows how his Kitchen finks loop works, and says after a few iterations “…and I will do this until I have gained 10,000 life”. They have determined a loop and can state what the game state will be once they have completed iterations of that loop.

The problem with Four Horsemen is that you cant say what the entire game state will look like when you have completed the loop to satisfaction. “You will be dead, but I dont know if it will take 6 goblins, or 16,000 goblins to do so.”

This could be relevant to the inactive player if they are holding a rakdos charm in hand for example.

So we've come to a situation where a player can't take a shortcut and must play out every interaction?
That feels like it should be classified under the same circumstance as the legacy deck to me.

The difference is that with the legacy deck there is a point, after the emrakul trigger has resolved normally that the gamestate looks exactly the same apart from a few more triggers meaning that the game state hasn't advanced

The problem with the infamous “Four Horsemen” deck is that the end point is indeterminate; while it has a statistically significant likelihood to end in the desired result, the number of steps to get there can not be determined. Seems like this is the same thing, essentially.

Or: If it looks like durdling, feels like durdling (esp. to judges and opponents) and smells like durdling … it IS durdling.

d:^D

To execute a loop, you need to be able to define the outcome you desire,
the steps that are needed to reach that outcome and a maximum number of
iterations it will take to reach the desired outcome. Because of the
randomness inherent in Goblin Test Pilot, you can not definitively state
the maximum number of iterations required to reach the desired outcome.

A few years ago, Matteo Callegari and myself wrote an article on Slow Play
and included a section regarding the Four Horsemen in Legacy.

http://blogs.magicjudges.org/articles/2012/12/25/slow-play/#loops

Slow Play hasn't changed much since publishing and the section on Loops is
still relevant to this discussion.

Is there any validity to saying “Okay, I cant shortcut this, so I'll just play it out, then when I win game one, there's no way game two will end”

It feels like we have a game state that we can't shortcut, so we just have to do it “by hand”.

This sounds very similar to how eggs ended up having to do things

Originally posted by Gareth Tanner:

This sounds very similar to how eggs ended up having to do things

Not having played in a format where a viable Eggs deck showed up to the party, are these truly similar? Was the number of possible iterations for Eggs to win potentially infinite, as here? Or was there some limitation to the number of iterations, such as the size of the library?

This actually doesn't sound too bad - it looks scary slow-play-wise when written down, but when you think about actually doing it - assuming the opponent hasn't gained life up to a huge number, and doesn't have a vast token army (and even if they do, it'll soon be whittled down) - it can actually be done fairly quickly* (even if the opponent doesn't scoop as soon as they see it start…). Statistically, it could in theory never win, but in practice it will, and it won't take too long.

I'm inclined to the view that doing it manually is advancing the game state (due to the growing pile of creatures etc. - if this isn't advancing the game state, then neither are most Modern Twin decks…).

Since the actions are advancing the game state, and it won't be as slow to get anywhere as things like Eggs, this seems fine to me.

(I wouldn't try pulling it off in MTGO, though…)

* When I say that it's reasonably fast, I'm imagining a player who understands the deck well and knows what they're doing moving through it promptly. I wouldn't like to face someone who was uncertain of how to do it and was playing hesitantly.

Edited James Winward-Stuart (July 17, 2015 12:19:07 PM)

Originally posted by James Winward-Stuart:

I'm inclined to the view that doing it manually is advancing the game state (due to the growing pile of creatures etc. - if this isn't advancing the game state, then neither are most Modern Twin decks…).

If this is true, would you be okay with a Splinter Twin + Deceiver Exarch player manually executing the steps of his loop to create one million tokens, rather than using a shortcut?

Is this a real deck or just a fictitious scenario to discuss policy? There are a lot of better options to combo out instead of the Goblin Test Pilot that lead to deterministic loops.