Here's my thought on reading this, and perhaps the answer is trivial, but it's not something I can understand:

Let's say you have a deck and you present it to an opponent, and let's say your opponent is the most skilled sleight-of-hand magician (pun intended) in the world who can manipulate the cards in any way he likes without you noticing, but he has to play by the following simple rules that we enforce through Magic policy:

1) He is not allowed to look at the face of any card (GPE - LEC)
2) There is no way to differentiate any card from any other card without looking at the face (TE - Marked Cards)
3) The deck is sufficiently random (TE - Insufficient Randomization) and therefore neither player knows the location of any card in the deck.

Challenge: Provide a deterministic method by which this opponent is able to stack your deck in any way to benefit himself.

While I am not well-versed in manipulation, it seems to me as though, assuming the above things are true, the issue being discussed here, i.e. that of the opponent cheating by stacking your deck, should be impossible. If your opponent is successful in stacking your deck by using the “last touch” rule to his benefit, that means one of the following things is likely true:

1) Your opponent cheated first by looking at cards he was not allowed to, and you should have called a judge at that point.
2) You need to replace your sleeves, because your cards are marked.
3) You did not sufficiently randomize your deck to begin with, and ought to shuffle better.

Not to say that your opponent stacking your own deck to his benefit is ok at all, but rather if you are paranoid about this happening to you, there are methods by which you can protect yourself so that you don't have to resort to the last and final measure of giving your opponent the opportunity to cheat in this way in the first place, and furthermore you ought to do these things anyway because you are compelled to do so by the rules of Magic.

Edited Lyle Waldman (Sept. 6, 2016 02:23:13 PM)

It's not always obvious when your opponent is able to see your cards.

Originally posted by Isaac King:

It's not always obvious when your opponent is able to see your cards.

Counterargument: If your opponent is able to see your cards, one of the following things have happened:

1) You have shown your opponent your cards (by accident), in which case you should probably figure out what it is you're doing that results in this and stop doing that.

2) Your opponent has illegally looked at your cards without your permission, which I find it hard to believe is possible without being relatively forward about it (e.g. looking downwards while shuffling the cards with the cards facing upwards towards him), in which case you ought to call a judge. Perhaps there exists a way to shuffle an opponent's deck while seeing every card without being noticed, but for the moment it seems sufficiently difficult to do that I'm willing to discount it.

Originally posted by Lyle Waldman:

Isaac King
It's not always obvious when your opponent is able to see your cards.

Counterargument: If your opponent is able to see your cards, one of the following things have happened:

1) You have shown your opponent your cards (by accident), in which case you should probably figure out what it is you're doing that results in this and stop doing that.

2) Your opponent has illegally looked at your cards without your permission, which I find it hard to believe is possible without being relatively forward about it (e.g. looking downwards while shuffling the cards with the cards facing upwards towards him), in which case you ought to call a judge. Perhaps there exists a way to shuffle an opponent's deck while seeing every card without being noticed, but for the moment it seems sufficiently difficult to do that I'm willing to discount it.

Trevor Humphries is banned because he made this kind of trick numerous times, even on camera and won tournaments without anyone noticing, so is not that hard to believe, search his name on youtube if you want to see him in action.

It takes an exceptional amount of skill and practice to pull it off and he was still (eventually) caught. Humphries is the exception, not the rule.

If we are discussing the “I should get to touch my deck last” proposition still, I have a question.

Isn't every argument made about the potential skills of your opponent also applicable to the person owning the deck? If we were to implement a policy where they get last touch, all arguments would be the same but reversed?

So are we even discussing the original question anymore :)?

Originally posted by Eskil Myrenberg:

If we are discussing the “I should get to touch my deck last” proposition still, I have a question.

Isn't every argument made about the potential skills of your opponent also applicable to the person owning the deck? If we were to implement a policy where they get last touch, all arguments would be the same but reversed?

Not quite. There are a couple things under consideration here:

1) As the owner of the cards, you know your own cards, and your opponent doesn't. This is an argument made earlier in the thread by Uncle Scott (and others) whereby you make, for example, all your Siege Rhinos (the name is in my head because I just watched the Trevor Humphries video) in very slightly shorter sleeves, and when you get last touch of your deck, you shuffle (or cut) it such that you always draw a Rhino. Similar examples exist in other situations, but generally follow the pattern of: In preparing your deck, make your sleeves non-uniform, then when you get last touch of (your own) deck, cut the deck so one of the marked cards is on top. Marked cards can go just as unnoticed as the Trevor Humphries shuffle (arguably more unnoticed, tbh).

2) In Victor's defense, he is suggesting a final /cut/ of the deck, not /shuffle/. Therefore most of the arguments against the opponent getting last touch don't apply, because most of them involve cheats involving a /shuffle/ (e.g. pile shuffling a player who has mana weaved to get their lands into one spot and manascrewing them, or doing the Trevor Humphries shuffle, or etc). Therefore a “final cut” seems fair (I think others have already pointed out why a final cut is just as unfair to the opponent as a final shuffle for the opponent is for you, plus I've outlined it above, so, just to be clear, it isn't, but it /seems/ fair, and Victor is providing a perfectly valid, if uninformed, concern).

As for the Trevor Humphries situation, while I only saw it from above, where the cheat is fairly obvious, and maybe it's not as obvious if you're sitting across the table, he tilts the faces of the cards upwards as he shuffles and looks down at them (or at least doesn't look away). This should be a giant red flag. That said, if he managed to do it a lot and never get caught, he is probably a lot more skilled at it than it looks in the video I saw.

To be fair Lyle, it is always easier to find something when you already know what and where to find it.
While I am cautious when I play, I do not start each match spending all my energy watching how my opponent shuffling my deck.
Skills of cheating is not based only on card manipulation skills, you also have to have the bahaviour that goes with it.

The way to prevent cheating is education (of players and judges) and vigilance, not toggling the shuffling rules back and forth.

As a magician for the past 18 years, with a decade of pure card Sleight-of-hand training, I feel I can offer some insight into the question of shuffling and manipulation.

For starters, it's not that hard.

Grab your deck and try this. Do a simple Overhand shuffle (the one where you pull packs of cards off with your thumb) but only draw one card first, the top card. Now it's on the bottom.

Congratulations, you just cheated!

Ok, dramatics aside, you would have to know the top card first in order to gain any advantage. Oh that top card was a land when I need a spell? Bye-bye! This means you have gained information from a simple deck shuffle. And here, the shuffle is completely legit, minus the known location of the top card, now on bottom. But what if it's a card you really want?

Do another Overhand Shuffle, but this time pull off a pack of cards with the thumb and, at the same time, apply pressure to the bottom card with your middle and ring fingers to draw the bottom card out. When you complete the pull, the bottom card will be right back where it started, on the bottom. Complete the shuffle. Now do a legit Overhand shuffle but make sure that you pull the last few cards individually so the bottom card is now on top.

Congratulations, you have done what we call a “false shuffle”. It is a shuffle that looks legit, but in fact there is an element of control. Now, obviously there are plently of other methods of false shuffling, some much harder to detect than the rest, but it all comes down to the amount of control the shuffler has over the cards.

That's what we're talking about when we we consider shuffle manipulation. How much control is the shuffler applying to the cards? When a person shuffles, there should be ZERO control, hence why it's randomization. Once any small modicum of control is put into the shuffle, it is no longer legit. This is an absolute.

Originally posted by Lyle Waldman:

Let's say you have a deck and you present it to an opponent, and let's say your opponent is the most skilled sleight-of-hand magician (pun intended) in the world who can manipulate the cards in any way he likes without you noticing, but he has to play by the following simple rules that we enforce through Magic policy:

1) He is not allowed to look at the face of any card (GPE - LEC)
2) There is no way to differentiate any card from any other card without looking at the face (TE - Marked Cards)
3) The deck is sufficiently random (TE - Insufficient Randomization) and therefore neither player knows the location of any card in the deck.

Challenge: Provide a deterministic method by which this opponent is able to stack your deck in any way to benefit himself.

This is easy. One, any person competant in shuffling will know about shuffle tracking and patterns can, with a decent amount of approximation, shuffle in such a way that might make it detrimental to the opponent. Has your opponent scryed any cards to the bottom? Obviously didn't want those; lets give them back to him!

But here's why this problem is easy: Your assumptions are flawed from the get go. I could care less about your rules and safeguards if I'm cheating.

It bears repeating: Cheaters. Don't. Care. About. Rules.

Else, they wouldn't be cheating. It's perfectly fine to imagine a perfect scenario in a lab-controlled environment like the rules you describe above. That's cool, but in reality, I'm not going to observe a single one of those and do all within my power to cheat you. This is how cheaters function. They are playing a different game than you are.

There is one facet about the sleight-of-hand that has not been touched upon, and it's the “why” of successful cheating. Why do you think people like Trevor Humphries or Alex Bertoncini (sp?) cheated for so long and never got caught? How could the do these moves right under the noses of players and Judges without ever as much of a second glance?

It's called Misdirection. A fundamental skill in magic, it's what makes come of the grandest illusions possible in the world. It is the art of guiding someone to look somewhere you WANT them to look, so that they are not looking where they SHOULDN'T. Answer me this: Do you watch people shuffle your decks when you pass them? That's good, you should always do that. Now, how about when your opponent is talking to you about your masterful blocking in the previous game? Or that one spell combination that locked him down? You will probably look him in the eye for a few seconds, because that's just polite manners, right?

A few seconds is all I need.

Hand gestures, head nods, “accidentally” dropping cards, moving your chair forward, pointing out the large crowd, these are all examples of Misdirection, because they can distract your focus. One of my favorites is asking where the bathrooms are or where to turn in the match slip. I can guarentee with 100% accuracy that, when asked that question, you looked around to find the answer and “help” your opponent.

You did indeed, and he helped himself to stacking your deck in the interim.

Now, granted, this all takes time to do, but watch some of the Trevor Humphires videos. They are fantastic in what tey can teach. Sure, you can watch for the cheat and see it pretty clearly. But now watch what Trevor is doing while he cheats. He's talking, engaing the opponent/Judge/anyone around in his bubble of Misdirection so that no one is aware of what he's actually doing. Always remember, Trevor was caught from video replay, not in the act.

As a last statement, let's not forget that cheating in magic at this level is fairly uncommon and it's not a rampant problem as much as the internet likes to make it. Sure, there are cheaters out there, and we do our best to catch them, but not every other player is a card shark. Just protect the integrity by observing the important action (the shuffle) and don't allow yourself to be led to look somewhere else. I believe 100% that watching a player shuffle isn't rude or insulting (as Scott Marshall points out, in some cultures it may be and I concede that point). It's simply protecting the integrity of the event and your match.

If you have any questions about sleight-of-hand in magic, feel free to ask.

Ghost_Stache

(Sorry it's so long!)

Edited Kyle Gorbski (Sept. 7, 2016 09:20:57 AM)

I realize I never actually answered the quesiton about the shuffle policy. In short, it's fine. As Riki Hayashi points out:

Originally posted by Riki Hayashi:

The way to prevent cheating is education (of players and judges) and vigilance, not toggling the shuffling rules back and forth.

Adding in another layer to the policy just adds more opportunity for mistakes and bad decisions. Cheating prevention comes proactive engagement, not restrictive policies. Again, cheaters sole direction is to get around policies and find new ways to circumvent it. That's why we have strict penalties for those who are caught. TRying to alter policy in such a way to make it more restrictive on players is more of a burden than a help. Just be aware of the match and educate yourself and others.

Cheating isn't all that hard, to be completely honest. But being aware of it is equally as easy.

Ghost_Stache

(I would also like to state I've NEVER cheated in any game of MTG, nor will I ever. I play with complete honesty and integrity. I just know magic tricks and how to move cards around, that's all)

Originally posted by Kyle Gorbski:

Lyle Waldman
Let's say you have a deck and you present it to an opponent, and let's say your opponent is the most skilled sleight-of-hand magician (pun intended) in the world who can manipulate the cards in any way he likes without you noticing, but he has to play by the following simple rules that we enforce through Magic policy:

1) He is not allowed to look at the face of any card (GPE - LEC)
2) There is no way to differentiate any card from any other card without looking at the face (TE - Marked Cards)
3) The deck is sufficiently random (TE - Insufficient Randomization) and therefore neither player knows the location of any card in the deck.

Challenge: Provide a deterministic method by which this opponent is able to stack your deck in any way to benefit himself.

This is easy. One, any person competant in shuffling will know about shuffle tracking and patterns can, with a decent amount of approximation, shuffle in such a way that might make it detrimental to the opponent. Has your opponent scryed any cards to the bottom? Obviously didn't want those; lets give them back to him!

But here's why this problem is easy: Your assumptions are flawed from the get go. I could care less about your rules and safeguards if I'm cheating.

It bears repeating: Cheaters. Don't. Care. About. Rules.

Else, they wouldn't be cheating. It's perfectly fine to imagine a perfect scenario in a lab-controlled environment like the rules you describe above. That's cool, but in reality, I'm not going to observe a single one of those and do all within my power to cheat you. This is how cheaters function. They are playing a different game than you are.

I feel like you missed an important feature of the points I made: Specifically, two of them are in the total control of the person on the receiving end of the cheat. That is to say, if you are afraid of being cheated:

1) Don't play with marked cards. They can and will be used against you, both by judges (to give you TE - Marked Cards) and by some less-than-wholesome opponents. But even if you don't care about less-than-wholesome opponents, you still shouldn't do it, because judges care.

2) When you shuffle, shuffle thoroughly. Don't just pick up your deck, mash it once, and present. Give it a few mashes, or a good overhand, or even better, a combination of the two. Once again, not only will your unscrupulous opponent take advantage of your lack of sufficient randomization, but you can get a tournament penalty for it as well. You may not get last touch, but you get first touch, and when it comes to randomizing your deck properly, first touch is more important than last touch (assuming you're not planning anything fishy yourself)

If you do these two things, you are 90% of the way to not being cheated (in the way of cheats by opponents stacking your deck; there are certainly many other ways to cheat at Magic, but that's beyond the current discussion), and these two things are completely under your own control.

So yeah, perhaps if your opponent is good at misdirection and sleight of hand, you're not completely in the clear, but the number of people who are Trevor Humphries or Alex Bertoncini are dwarfed by the number of “script kiddies” (to borrow a term from Computer Science) who try simple tricks which are easily stopped by just playing Magic the way the rules tell you to do so anyway.

Edited Lyle Waldman (Sept. 9, 2016 11:20:47 PM)

Yes, these are in control of the player, but the deck doesn't END with the owner. It ENDS with the opponent when presenting.

For one, Marked Cards has very little to do with false shuffling. Competant magicians can do these blindfolded. We have spent decades devising methods of controlling cards without looking at them. We don't need Marked Cards to be able to tell. And again, I can look at a card without you knowing.

Two, we all shuffle throughly, I don't think that point is in contention. But the issue is that we don't end by shuffling. We end by passing to opponent and THEY get to shuffle. Which is where the cheating occurs.

Again, I would like to stress that we all try to play by the rules, yet there have been high-profile cases of cheaters on camera. Their opponents were playing by the rules, but the cheaters were not. This is absolute. It is fundamental to examine that cheaters play a different game than you or I do. That's why it's cheating.

So by just playing Magic the way the rules tell us to is just fine. We have safeguards in place. But when we present the deck to our opponent, the way the rules tell us to, the last touch of our deck is NOT in our hands. So when you talk about how 90% of cheaitng can be prevented by being proactive on your side ignores the fact you leave the deck in your opponents hands.

Ghost_Stache

Originally posted by Kyle Gorbski:

Yes, these are in control of the player, but the deck doesn't END with the owner. It ENDS with the opponent when presenting.

For one, Marked Cards has very little to do with false shuffling. Competant magicians can do these blindfolded. We have spent decades devising methods of controlling cards without looking at them. We don't need Marked Cards to be able to tell. And again, I can look at a card without you knowing.

Two, we all shuffle throughly, I don't think that point is in contention. But the issue is that we don't end by shuffling. We end by passing to opponent and THEY get to shuffle. Which is where the cheating occurs.

Again, I would like to stress that we all try to play by the rules, yet there have been high-profile cases of cheaters on camera. Their opponents were playing by the rules, but the cheaters were not. This is absolute. It is fundamental to examine that cheaters play a different game than you or I do. That's why it's cheating.

So by just playing Magic the way the rules tell us to is just fine. We have safeguards in place. But when we present the deck to our opponent, the way the rules tell us to, the last touch of our deck is NOT in our hands. So when you talk about how 90% of cheaitng can be prevented by being proactive on your side ignores the fact you leave the deck in your opponents hands.

Ghost_Stache

I feel like we're arguing past each other. I grant you: If you can get information of the identity of the cards in the deck, then yes you can use some kind of shuffle cheat to stack the deck. This is undeniably true. My point is that the number of people who can actually do this proficiently is sufficiently small as to make this particular avenue of cheating not something worth worrying about (in practical terms; obviously it's something worth worrying about in policy, cheating is cheating and cheaters get DQ'd.). If you are an average player, who plays Magic with other average players, and it occurs to you that you ought to be concerned about your opponent getting last touch because you think he can stack your deck, the chances are very high that either a) he's not actually going to do that, or b) if he's going to try, and you have protected yourself adequately by shuffling thoroughly and not using marked sleeves, he's going to do it poorly enough that you will catch him, and we have methods of dealing with such people.

Yes, there are people who are proficient at sleight-of-hand, misdirection, or other such magic (not to be confused with Magic) techniques, and those people will actually scum you and actually cheat and actually get away with it (for a time, and then they'll get caught, DQ'd and get a 4-year DCI ban, and possibly throw a hilariously awful rant on Facebook for all to see). But those people are so few and far between that it is, as a rule, not worth considering that this is a thing that is going to happen to you, realistically speaking.

Edited Lyle Waldman (Sept. 7, 2016 03:01:32 PM)

Originally posted by Lyle Waldman:

…because most of {the} cheats {involve} a /shuffle/ (e.g. pile shuffling a player who has mana weaved to get their lands into one spot and manascrewing them

This is not an example of Cheating; it was listed under Cheating until February, 2014, when we confirmed that it's not, in fact, Cheating.

d:^D