How do I respond if challenged on an obscure infinite loop?
Asked by RicketyEng 4 years ago
My question is this: given the infinite loop (described below) that is achievable using the above cards, what is the best way to prove that it works if someone doesn't believe me at first demonstration?
The loop is as follows:
1) Have Gitrog in play, Ulamog in the library, Dakmor Salvage and more than 7 cards in hand.
2) Move to the cleanup step of your turn where you will need to discard down to 7 cards. Make sure that at least one of the discarded cards is a land. This will trigger The Gitrog Monster 's draw ability.
3) Players do not normally get priority during the cleanup step, but since there was an ability triggered, it needs to be put on the stack and resolved in the normal fashion.
4) Draw a card or, if Dakmor Salvage was discarded, dredge it. If one or both of the milled cards are lands, then Gitrog will draw you an additional card.
5) Once the stack is empty and priority has passed around, the cleanup step begins again and you should now have greater than 7 cards again and must discard. Repeat this loop from Step 2 until you find Ulamog.
6) Ulamog, the Infinite Gyre will either be found by being milled in the dredging of Dakmor Salvage or by drawing him off one of the extra cards drawn. Whenever he is milled he will cause your graveyard to be shuffled into the library. Whenever you draw him, make sure he is among the cards discarded at the next opportunity.
Conclusion: With Ulamog recycling the graveyard this loop can be done a truly infinite amount of times and can be used to sift through your deck to select any 6 cards to keep in addition to Dakmor Salvage. It can also go one step further to keep that hand and arbitrarily stop immediately following a reshuffle.
Therefore as a shortcut, this loop can be used to select a hand from your graveyard and library while also shuffling your graveyard into your library following the selection.
For someone who hasn't put a lot of thought into it yet, this can be a hard conclusion to jump to. If I demonstrate the Dakmor/Gitrog part of the loop then reveal Ulamog from my library, should I be able to shortcut to selecting my hand and shuffling? It is an extremely time consuming loop if it can't be shortcut. How should I proceed if someone doesn't believe my conclusion?
RicketyEng says... #2
I have no doubts about how the combo works. I'm just looking for the advice for how best to go about short cutting it when I actually do it. So yeah, I guess anyone who has seen it before won't argue and will appreciate the shortcut. Meanwhile if someone hasn't seen it before it should be sufficient to step through the process a few times to demonstrate it before suggesting my shortcut.
My win condition to search for is normally Borborygmos Enraged .
October 24, 2019 4:51 p.m.
Gidgetimer says... #3
The Gitrog loop is not deterministic, so you can not technically shortcut it. Most players should be cool with you sculting your hand or presenting your win con, but if someone wants to be a jerk they are technically correct (the best kind of correct) in making you play it out. It runs into the same problem that four horseman has in legacy. Though highly unlikely it is possible that you dredge Ulamog before your win condition every time you do it in whatever time frame you have to play.
October 24, 2019 11:26 p.m.
Rhadamanthus says... Accepted answer #4
You can't shortcut through the loop you're describing because it doesn't have predictable results and isn't guaranteed to halt in a finite number of steps. Because of the randomness introduced by the shuffle there's no way to predict how many times you'll need to loop through the actions to get to your desired end state and there's a possibility you'll never actually get there. It also includes a bunch of conditional actions that depend entirely on the unpredictable results of the preceding step.
Comprehensive Rules 721.2a: At any point in the game, the player with priority may suggest a shortcut by describing a sequence of game choices, for all players, that may be legally taken based on the current game state and the predictable results of the sequence of choices. This sequence may be a non-repetitive series of choices, a loop that repeats a specified number of times, multiple loops, or nested loops, and may even cross multiple turns. It can't include conditional actions, where the outcome of a game event determines the next action a player takes. The ending point of this sequence must be a place where a player has priority, though it need not be the player proposing the shortcut.
Magic Tournament Rules 4.4 (excerpt): Non-deterministic loops (loops that rely on decision trees, probability or mathematical convergence) may not be shortcut. A player attempting to execute a nondeterministic loop must stop if at any point during the process a previous game state (or one identical in all relevant ways) is reached again. This happens most often in loops that involve shuffling a library.
October 24, 2019 11:34 p.m.
dingusdingo says... #5
The list I linked covers exactly the things you're looking for. I can't stress enough that you should read the the primer with that decklist before you ask any more questions as it covers this combo extensively and in great detail. I want to help you further but like, come on dude, you have to meet me halfway here. You're like a patient dying at the doctors office because they won't take the medicine for a curable disease. Even if you aren't playing this combo in EDH, it still works the same in whatever format you're in.
One more time for you
https://tappedout.net/mtg-decks/gitrog-land-combo/
I'll even get the important bit out for you
:(
On Shortcuts & Slow Play At this point, you might wonder if the Dakmor Combo is shortcuttable. Simply put, the answer is yes and no. The rules of shortcutting only include loops, as in actions that you can perform indefinitely, that don't include any conditional factors, which this combo has plenty of due to having the possibility of milling between a nonland card, a land card and a shuffler (Kozilek/Blessing) every time you dredge Dakmor. After you've drawn your deck these conditional factors can be removed and the true "loops" may begin, but when you're emptying your library there are no ways to avoid them. Due to this, you will have to play out the "draw my deck" part of the combo in sanctioned environments unless your opponents agree to unanimously concede once you've assembled it.
However, sometimes people might start to shout slow play accusations if they're any familiar with tournament conduct and would like to abide by them (rare in an EDH table, but possible nonetheless). Luckily, despite the annoyingly long resolution of the "draw my deck" part of the combo, the combo is what is called "deterministic"; something that ultimately reaches the same outcome in all permutations it is able to produce. Another way to describe it rules-wise is that because it is not exactly a "loop" as described by the comprehensive rules:
719.1b "Occasionally the game gets into a state in which a set of actions could be repeated indefinitely (thus creating a “loop”). In that case, the shortcut rules can be used to determine how many times those actions are repeated without having to actually perform them, and how the loop is broken" On a related note, here is the ruling on slow play as described in blogs.magicjudges.org:
"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" As you can resolve one or multiple draw triggers on each iteration of the "loop" if need be, you can perform the combo so that you can essentially only continue to dredge cards as long as you have cards left in your library, making the set of actions definite as long as the total amount of cards in your library and graveyard keep decreasing.
This is why it's not "slow play" like Four Horsemen is because it's not an indefinite loop with no end, but a sequence of actions with differing outcomes that alter your play lines accordingly.
If the judge or players become particularly persistent on how the lines are still slow play, I'd demonstrate the 1B line of drawing the deck as follows:
"With the combo in place, I'll begin to dredge Dakmor and mill cards to empty my library. Whenever I mill a land, a draw trigger will occur and I will resolve it to draw a card. If I mill into Gaea's Blessing or Kozilek, Butcher of Truth , in response to the shuffle trigger, I will keep dredging Dakmor and milling cards until my library is empty, drawing a card whenever I mill a land from the dredge. After emptying my library, I will resolve the shuffle trigger, and repeat this sequence of actions for about 7 times to ensure my library and graveyard are completely empty at the end of it. After reaching this end state, I will keep discarding Kozilek and shuffling it to my empty library to get rid of any surplus triggers that I may have accumulated during these 7 or so shuffles." Of course, you can and should state a specific number without being vague in the line above, I just went with "7-or-so" to call the bare minimum for the amount of shuffles one has to perform to empty the library.
To add to this, this Reddit post has some attached mathematical proof for the deterministic nature of the combo, in case someone is looking for a run on the numbers for the more resilient lines.
At the end of the day, in sanctioned tournaments it's up to the judge to decide whether to give out a slow play warning, as the rules of slow play are extremely vague and could be written dozens of articles about. Due to the combo's deterministic nature however, you are able to demonstrate that you are able to win no matter what unless people are going to try and disrupt you while you draw your deck (and these are usually rare occasions themselves). This is why it has been allowed so far in the community's leagues I've played the deck in.
Of course, even though I'm constantly mentioning sanctioned tournaments, EDH is over 90% of the time played in a more lenient environment when it comes to rules enforcement, so most people should not have a trouble with the combo by default. Anyway, it's still a good discussion to have with your playmates when starting to play with Gitrog, especially if you're going to apply for an event with prizes on the line.
To give some closure to this controversy, the most time-consuming part of the combo is fortunately over after emptying your library and graveyard. From here on every play line is a legitimate, shortcuttable loop with the KoziLand technique as well as the other loops provided, so as long as you remember the lines things can be executed relatively fast. Time to proceed on to how we win the game.
October 25, 2019 2:24 a.m.
Gidgetimer says... #6
While what dingusdingo linked for deterministically drawing your deck works for when you have a discard outlet, using the cleanup step to discard is non-deterministic because you do not get to discard Dakmor to dredge Dackmor until after all triggers have resolved.
October 25, 2019 7:18 a.m.
Rhadamanthus says... #7
The shortcut rules don't allow for a loop to have conditional actions. The algorithm with a discard outlet in the Reddit post is full of conditionals. If you can find a judge who will rule in your favor, fine, they're the boss, but I wouldn't agree with them. As far as I can reason, the rules as-written don't allow for shortcutting this loop. I guess this makes my response an opinion rather than a "real" answer so take that as you will.
October 25, 2019 10:09 a.m.
RicketyEng says... #8
Hmm, ok, so the cleanup step version of the loop (the version I use) is strictly speaking not allowed to be shortcut according to the Tournament Rules. What exactly is the scope of the Tournament Rules (I rarely play in tournaments so I am not familiar with some of those rules)? I'm mostly trying to learn how I need to treat this loop in various settings where I might use it.
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Around the kitchen table: definitely ok to shortcut and probably encouraged for brevity's sake.
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Casual store event: maybe ok to shortcut, but only after all players understand it and agree. They also may encourage the shortcut for brevity's sake.
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Sanctioned (EDH) tournament: not ok to shortcut by default. However, if opponent agrees to get a judge's ok then it might be ok to shortcut?
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EDH on-demand games at a Magic Fest: where does this one fall into the above categories?
PS. Dingusdingo, I did in fact read that primer so I will be accepting absolutely no shame.
October 25, 2019 3:13 p.m. Edited.
Gidgetimer says... #9
The shortcut rules are in the comprehensive rules, not the tournament rules. Casually how it is handled will depend on your opponents. In sanctioned events including magicfests (where tournament rules are in effect) you will probably be given a warning for slow play.
October 25, 2019 4:02 p.m.
Rhadamanthus says... #10
The Magic Tournament Rules document has additional clarifying rules on how to handle loops in an event: link to a web-based version
dingusdingo says... #1
There's a guy at my LGS who plays Gitrog dredge. He will normally just call a Judge to verify the interactions if anyone hasn't seen it or doesn't know how it works. If you're playing with friends, it shouldn't be too difficult to explain once you've shown it once or twice through. If you're in an environment where there isn't a judge, you aren't going to get slow play called on you, but they may make you play the loop out. This combo isn't very obscure though, and anyone who has played commander in shops and out and about has probably seen a Gitrog deck and may just scoop when you start hand sculpting with the end step.
I highly recommend looking at this list, as they explain the Gitrog combo in great detail.
https://tappedout.net/mtg-decks/gitrog-land-combo/
If you're interested in more information on looping and slow plays, look at
https://blogs.magicjudges.org/rules/ipg3-3/
To answer your question definitely though, here is what you're looking for
514.3. Normally, no player receives priority during the cleanup step, so no spells can be cast and no abilities can be activated. However, this rule is subject to the following exception:
514.3a At this point, the game checks to see if any state-based actions would be performed and/or any triggered abilities are waiting to be put onto the stack (including those that trigger "at the beginning of the next cleanup step"). If so, those state-based actions are performed, then those triggered abilities are put on the stack, then the active player gets priority. Players may cast spells and activate abilities. Once the stack is empty and all players pass in succession, another cleanup step begins.
Also worth noting, if you use this method, you WANT a method of winning off of it. Check the gitrog I linked for a line.
October 24, 2019 4:28 p.m.