The in and out transition attack drill is pretty basic, but it is going to work on the players ability to attack off the dribble in transition, more specifically with the in and out move. If you look at a player like Russel Westbrook or Kyrie Irving you can see their ability to be able to attack at close to full speed in transition, and then make a quick hesitation or change of direction move to get past the waiting defender. This is something that they have worked on and developed, and it has made them extremely hard to guard in transition.
Every move in this basketball drill is going to involve the in and out move, so it is important that you really learn to sell the move. Also it is important that you don't worry about losing the ball. That sounds like the opposite of what it should be, but what I mean by this is, the drill is the place where you should be challenging yourself to go full speed, and if you lose the ball, simply try again. That way you will be prepared to use this move in a real game. Going half speed during your basketball training isn't going to cut it.