Investigations – The Search for Collateral Truths


Editor’s note- We are pleased to present this article as the first in a series on investigations by Player Investigation Leader Eric Shukan.

Written by Eric Shukan

Written by Eric Shukan


In my role as Player Investigations Leader I have seen countless DQ reports.  While some are simple and straightforward, a great many involve conflicting stories or incomplete evidence.  These are the ones in which the FJ’s and the HJ’s investigative technique and philosophy can make or break the final decision.


Over the years I’ve seen articles about body language, how to ask questions of players, and generally how to handle the emotional aspect of the investigation so that you can get information.  This article series instead focuses on how to determine what questions to ask and what information will likely be useful.  Once you understand what information would be useful, you can employ those emotional techniques to try to obtain that information.  But first you need to know what information you want and how likely it is that you’ll be able to get it, and that is mostly an exercise of logic.

Inspired by actual cases from the Investigations Committee, I present a 3-part series on how to decide what information you want and then how to evaluate information that you get.  Part 1 defines collateral truths and introduces the logic of the scientific method; Part 2 discusses motivations and probabilities that derive from those motivations; and Part 3 introduces the idea of how to know when to terminate an investigation, regardless of which way you will rule.

I would like to thank Jared Sylva for helping to shape some of the ideas in this series.  While he didn’t know it at the time, the discussions he and I had some years ago at one particular SCG Open solidified my concepts into something I can now articulate.  Also I would like to thank Alejandro Raggio, whose understanding of language helped shape the syntax for this article.


Part 1:  Verifying and Falsifying Collateral Truths

Investigations search for possibilities and seek to confirm or disprove them.  You should formulate a scenario in your mind about how things played out, and then seek to find evidence to support or contradict that scenario.  The mental construct of the scenario is called a hypothesis in the scientific method, and it is based on your understanding of reality.  Your attempt to locate evidence related to it would be the test.  Hypothesis-then-Test is the fundamental idea behind all investigation.

Start by asking yourself, “What do I THINK has happened?” This opinion may be based on the initial statements that players have made, writing on match slips, personal observation, or any other type of data.  This lets you put together a model that you can now test.  If that model is true, certain other things, called collateral truths, will also be true or very likely to be true.   Therefore, if you can show that a collateral truth is false or very unlikely, then the model you constructed will also be false or very unlikely.

If you want to investigate a story given by a player, start by investigating the collateral truths of that story.  This is related to the scientific method.  Let’s look at some examples.


Example #1

A spectator comes to you and says that he saw Player A put two cards from his lap into his hand.  You investigate a bit by doing a card count and find that on Turn 6 Player A has two extra cards.  Player A claims that he doesn’t know where they came from and didn’t notice drawing extra cards.  Now, ask yourself, “IF Player A is telling the truth, what else MUST be true?”  The answer is clear: the witness must be mistaken or lying.  But how likely is that?  For the witness to be mistaken in seeing cards from the lap is virtually impossible here.  To be lying, the witness needed to fabricate a story about the cards being in his lap AND would have had to get lucky in that Player A had two extra cards.  These two together are far too remote, and so you should conclude that player A has cheated and lied.  By falsifying the collateral truths to Player A’s story, you have falsified Player A’s story.  This is one way of making a direct conclusion.


Example #2

In a Round 1 deck check you find that player A has a small crease or “nail mark” on 18 of his 24 land cards in a constructed deck, and there are no markings on any other cards.  The markings are in the same place on each sleeve, and they may be visible simply by looking down at the library.  During routine questioning, player A tells you he just bought new sleeves and resleeved his entire deck, and he didn’t notice any markings (although he sees them now that you point them out).  How do you proceed here?  GL for Marked Cards Upgraded?  DQ for intentionally marking the cards to gain advantage?  These markings could be a factory defect or an intentional cheat.

Ask yourself, “If Player A is telling the truth, what else MUST be true?”  To answer this logically, you will have to form a mental picture in your mind about how things happened and what other things must also be true.  You can then test them.

In this case all the markings are on lands, and that is quite unlikely if he sleeved a randomized deck.  He must have separated out his lands and spells prior to sleeving, so you ask him how he sleeved, and he tells you that he separated the lands and spells before sleeving.  He also tells you that his friend Mark Smith helped him right before the tourney started.  If this is true, then Mark Smith should back up the story (another collateral truth).  You find Mark Smith at another table, and he says they did sort the lands/spells and then sleeved them with new sleeves.  If the player tells you which dealer, you might even ask that dealer to confirm that Player A bought the sleeves right before the tourney started.  You are testing the collateral truths.

So, you have tried to falsify the collateral truths, but they have held up.  This doesn’t prove that Player A is telling the truth, but it definitely supports his story.  At this point you may well decide that no further investigation is likely to get you anything which will change your mind, so you terminate the investigation and issue GL for Marked Cards – Upgrade.  In contrast, if Mark Smith said that he did NOT help Player A put sleeves on, you would have likely falsified Player A’s story and then concluded at least that Player A lied to you.

Note that even if Player A has lied, he might have lied because he got nervous or because he wanted to avoid a GL.  You still don’t know if he intentionally marked the cards.  The burden of proof for that determination is quite high, and that’s why we have the GL upgrade.


Example #3 – The Classic

In a Limited event, Player A is found to have two extra, on-color bomb rares (not on his decklist) in his 40-card deck.  He claims that he had put his deck into his bag and that some of the cards in his binders must have gotten mixed into his maindeck.  We see this frequently, and I personally have heard it THREE times in tournaments where I was HJ.  If his story is true, what else MUST be true?  Well, the extra cards would have had to be sleeved in the same color sleeves.  Then, they would have had to fall out of the binder into the deck, nice and neat.  They would have to be two specific on-color bomb rares, as opposed to any of the other 1200 cards in his binder.  AND two other cards have to fall out of the deck to get back to 40.  None of these things is particularly likely, but for ALL of them to be true is beyond belief, so the conclusion should be that he has cheated.  This is an obvious case, but it illustrates the idea of collateral truths quite well.


Example #4 – Another Classic

In a constructed PTQ, Player A is discovered during a Round 6 deck check to have 19 sideboard cards.  Four Extirpate cards are not listed on his decklist, and he is playing black.  When you question the player, he says that he was playtesting the Extirpates before the tourney started, and that he decided instead to use 4 Mind Rot in the sideboard.  He also said that he was in a rush and he had no other place to put the Extirpates so he put them into the deckbox, but he never used them.  What now?  Ask yourself, “If he is telling the truth, what else MUST be true?”  You can then test those other ideas.

You decide that his decklist might have a cross-out in the sideboard section.  You check, and it does.  “4 Extirpate” is crossed out, and “4 Mind Rot” is listed at the end.  No falsification there, in fact there is some confirmation.  Then you look to see if he really has no other place to put cards.  You check if he has a bag, but he doesn’t.  He has only a deckbox and a pen.  No falsification there.  Then you ask his last 2 opponents if they remember seeing him play Extirpate, but neither can remember.  No falsification there.  One by one you tested the collateral truths and you could not falsify anything.  Now what?

You rule DDLP for having extra playable cards in the sideboard, GL.  The evidence does not support intent and use of the cards.  No DQ, right?

And yet, an L2 judge and an L3 judge this year DQ’ed a player in the face of this quality of evidence, claiming only something like “I DQ’ed him to protect the integrity of the event”.  We ALL want to protect the integrity of our events, yet DQ’ing a player without valid and describable evidence damages your event.



When players tell their sides of the story, you should try to construct in your mind a model of the reality that they are claiming.  Then ask yourself, “If that model is true, what else must be true or is likely to be true?”  If you can prove those collateral truths to be false, then you can likely prove a story to be false.

Judge Jared Sylva put it a different way:  “Form a picture in your mind about what you think happened.  Now ask yourself, ‘What would change my mind? (falsify my ideas)’  Then go hunt for that info.”

If you can falsify the collateral truths, then you can falsify the main hypothesis.  That is a fundamental aspect of the scientific method, and it is the heart of logical investigation.  Attack the collateral truths.


Looking Ahead

In Part 2, I will explore the idea of risk vs. reward and discuss motive.  When players cheat, they usually have a significant and specific gain in mind.  Evaluating the possible gain and the timing of a situation is important to making a judgment about cheating.  Simply put, if the player thinks he has little to gain, he is less likely to cheat.  This is a sort of motivational collateral truth that can guide your decision when the weight of evidence is otherwise balanced.