Definition of Hi-Jack
Hi-Jack, also known as HJ, is a position on the poker table. It is the seat to the right of the cutoff. That is, the player in the Hi-Jack position will talk before the cutoff. If you start from the big blind and go to the right, you have big blind, small blind, button, cutoff and Hi-Jack. Hi-Jack is sometimes also called MP for "middle position". The player to the right of the Hi-Jack is called the Lo-Jack. The Lo-Jack on a 6 max table is also called the Under The Gun (UTG) player. He is the one who speaks first preflop.
The Hi-Jack, a delicate position
Hi-Jack is a difficult position to play. If a player opens before us and we call the bet, we may get 3beted in position by the cutoff or the button. If we fold too much, we are not profitable. It is probably best to 3bet the player who opens before us to isolate ourselves if we want to play a hand. On the other hand, if no one has opened before us and the cutoff and button fold, we are in position and will have plenty of credit after the flop.