Stop and Start 1 vs. 1

This is a good 1 on 1 battle drill.  Think about using this drill towards the end of practice for conditioning as players tend to push themselves more when competition is introduced.  To set up place four lines on the blue line as shown in the diagram. Place a coach in the center of the ice on each blue line with a bunch of pucks.

On the whistle the first player in each line skates to the opposite blue line, stops, skates back to the red line, stops, and skates back towards the blue line.  As the players stop at the red line, the coach places a puck just inside the blue line in between the two players.  The players then race for the puck.  The player who does not get the puck tries to catch the player with the puck from behind.  The player that wins the race to the puck gets a breakaway opportunity.

If you are focusing more on conditioning you can increase the the amount of lines the players are required to skate before racing for the puck.