Like many posting here: I prefer not to give away "free information." If they wanted to see my potential
bluff, then they need to pay off the bet to see. To this, I'd say that 95% of the time, I am not showing (and I can fully understand the decision some have of never showing). However, there are a few times where I think showing may be to your benefit:
- Playing "meta-game" rather than the hand. If (and this is a big "if" here) you have observing and adapting opponents, then sometimes showing your cards may set them up to fail on a future hand. Something like showing an uncharacteristically complete air-bluff upon forcing all others to fold may give you more credence to getting paid off when you bet "bluffy-looking" but with the goods at a future time. However, this deception is tricky to pull off and assumes that your opponents are observant and adapting. In most cases (at least at lower levels), your opponents are not to this description. Many fish are just playing their own two cards and not thinking in terms of ranges or table image; this play will do nothing here.
- Another situation where I think showing could be helpful to you is in casual homegames where the emphasis is on fun and social atmosphere rather than it is the game itself. This is especially true is you are hosting the "poker night." So you may potentially let your opponent know you played Ax in that specific way for this hand: so what? It keeps them happy and they will probably learn your play-style if you play regularly anyway (which many homegames do). Keeping a friendly atmosphere that seems more casual will keep them coming back. Even if you are playing for decent money, that is all the more reason you want to fish to keep coming back to you.
- Finally, another time I think showing might help you is if you think your opponent is likely to reciprocate AND you feel that you can utilize that information better than they can. Some players I play are super oblivious to ranges and how I reason about the hand: I can show more hands to them and they won't know what to do with that information. They just take away "oh, you bluffed me" and don't catch other factors like semi-bluffing or floating. Maybe I wasn't even bluffing. Sometimes the untrained eye just thinks that after seeing all I had was Ace High, but unrealizing that I had a missed straight draw etc. When they happily reciprocate in showing me their hand, I am much more capable of reconstructing how they played the hand and what ranges they are playing etc. In this scenario, I am showing my hand often against them; especially if heads-up and no one else "gains" from this "free information."
With all this said though, most of the time (maybe 95% or so) I am not showing and this is exponentially true if I think some player(s) at the table are better players than I am and/or able to reconstruct how I play and adapt to it in an exploitative manner.