Unbelievable

The hardest word to guess in hangman, according to science, is: Jazz. Composed of 75 percent uncommon letters (J and Z) and allowing only three chances at picking correctly, jazz is the perfect storm of Hangman trickery. It's kind of fitting, really. They say jazz is all about the notes they don't play.
Now let the competition be aware.

Here is the Challenge now with this four letter word: H _ _ J you have only 3 chances in it. Start the contest! And save a man to be hanged.
Don't spoil the fun!