Just about any form of bluffing COULD fit this definition. However, depending on the bluff, it might not fit this definition:POP Penalty Guidelines - Unsporting Conduct: Major said:• Attempting to manipulate a match through intimidation or distraction.
For some, a match is already a stressful situation. And to them, losing can be very emotionally distressful. But, you can't penalize a player for causing this kind of self-imposed emotional distress. If a player is already nervous, it's not your job to calm him down.POP Penalty Guidelines - Unsporting Conduct: Major said:Infractions in this category have a direct impact on event operation or cause a small degree of emotional distress to those around them.
So, plenty of things you do COULD distress your opponent. Your mere presence could be intimidating (ie., Yamato). That hairy mole on your neck could be distracting. The real question is, are you doing something purposely, unsportingly, and illegally.
Like NoPoke stated, you'd have to show me something that says it's forbidden to show cards in your hand to your opponent. Where does it say I have to use "due diligence" to keep my hand secret?