We ran an open event at Gen Con that played variants with brand new players. We play tested the Signal Variant with the Gen Con players.
The signal variant is where you stack your opponents chips in front of you with the order of which you think the players have advantage. Everyone else does the same thing and at any moment you can look around to see who everyone thinks have the current advantage. It can be used to bluff or bring attention to someone getting close to checkmate.
The variant played well and wanted to thank everyone for their feedback. I will be posting on the website the rules with all of the variants.