Software engineer Chris Beaumont visualized the strength of opponent hands in Texas hold 'em, given any other hand. This is based on counting about 1.3 trillion possible combinations.
Simply enter a card combination, and the grid shows the win-loss percentage differences for all possible opponent hands. Each card value (e.g. 2 or a King) pair is represented as a four by four grid to show each suit (e.g. heart or spade). The above is the strengths of an opponent's hand given you have a four of hearts and a queen of spades. Red indicates higher chances of you losing and blue indicates higher chances of you winning.
See also the grids for hand frequency and average hand strength.