Hello fellow judges!

Alex casts a Think Twice with no blue mana. After drawing a card, Niobe realizes the error and calls for a judge.
The judge issues a GRV to Alex and a FTMGS to Niobe.
Right before performing a backup, the judge discovers that Alex didn't played a land in his turn and he has a Scalding Tarn in his hand.

Should we take into consideration hidden informations when deciding to perform a backup or not?
Thanks in advance for your help! :D

Edited Jacopo Strati (July 31, 2017 11:09:49 PM)

No, we should not.

Information like that might influence an investigation, but is not a factor for applying the IPG's remedies.

d:^D

I do not not have a specific stance, but I do find interesting that the 2 first answers are so clear cut in favour of not using this information while the general line of the back up Policy of the IPG states that we should be careful when potential shuffles are involved.
While it makes sense not to sue hidden information, I however do not find clear indication that this is not to be taken into account, because after all, in this case, I can clearly see that depending on what I randomly put back on top of the Library, it may very well change the sequencing of the play and create a completely different line of play.

One big reason not to use this info was pointed out in another recent discussion: we might be revealing contents of AP's hand. If NAP knows the IPG well enough, she might be able to discern the reason we are not backing up here, which would be very bad. Also, even if she doesn't know directly, if she asks why we can't just back up, what do we tell her?

Sent from my iPhone

I think the problem of letting them shuffle away a potentially bad card is less bad than potentially giving the opponent hidden information.

Originally posted by Jacopo Strati:

Right before performing a backup, the judge discovers that Alex didn't played a land in his turn and he has a Scalding Tarn in his hand.

Are you assuming he had the Tarn in hand before casting Think Twice? Or are you assuming that he drew it?

Either way, you are making an assumption about the game state from hidden information and attempting to apply it to your fix. That's probably not best practices. Assumptions are bad.

What assumptions are you talking about?

We know that the player now has a fetchland in hand. In clear, that means so thesake of clarity :
- If we chose not to back up, that is fine, but that is probably the reason we are chosing not to back up, so, I guess that is a question mark,
- If we chose to back up, then the player has the knowledge of the top card of the Library, and if the card is not the named fetchland, it now poses as a threat for the organic continuation of the game.

Even if it is not fully developped, the extent the question of Jacopo is :
-Given that a fetchland is a BIG NONO when we are considering a back up, how much difference does it make if the opponent does not have the information that the player can actually shuffle his deck.
How the IPG tells you to consider only the moving piece already on the battlefield rather than also those in hand? To my knowledge it does not, and that is only a practice we think is good, although not written anywhere.
I find the question interesting. What does the more damage is actually quite the question.

Originally posted by Théo CHENG:

What does the more damage is actually quite the question.

Théo understood my thoughts at 100%.
Thanks for your help and your answers. :)

Originally posted by Jacopo Strati:

Should we take into consideration hidden informations when deciding to perform a backup or not?

The adament “no” answers trouble me. If we are not to consider hidden information when considering to back up a card draw, then that leaves two possibilities:
1) we see no randomization effects on the battlefield and can disregard that deterrence of backing up the game, meaning we will (almost) systematically back up when no “fetch” effects are present on the field.
2) we never back-up when judging any format where there is a library randomization effect, because the player could have one in their hand, meaning we will (almost) never back up.

Neither seems to abide by the philosophy behind back ups.

Originally posted by Justin Miyashiro:

we might be revealing contents of AP's hand

Originally posted by Floris De Baerdemaeker:

{not backing up} is less bad than potentially giving the opponent hidden information

…and those are just two reasons for my Answer.

d:^D

Edited Scott Marshall (Aug. 8, 2017 01:41:44 AM)

Scott, you meant {backing up with a shuffle effect in hand}, rather than {not backing up}, right? That's what Floris was suggesting.

Jackson, while I think a very strict reading of policy does point to your 2) as the outcome, in practice and from what I'm hearing from Scott and other judges in this thread, I think that we just pretend private information doesn't exist when making backup decisions, thus sometimes allowing players to play fetches and shuffle away a known card.

Another interesting question: if something with a shuffle effect has been bounced, and the opponent says “hey, they have a shuffle effect in hand, you can't back up!”, should we consider that? I suspect the answer changes to “usually yes, unless they lack the resources to use the shuffle effect before they would naturally draw the card”, since the IPG calls out "the ability to shuffle their library" as the operative factor, but I'm not totally sure..