The focus of this drill is to increase the defensive players speed going backwards. The faster players can skate backwards the better gaps they are able to achieve. The ability for defense to match the speed of an oncoming forward is a great skill. To set up, form one lin on each blue line facing each other. The lines should be off set by a couple of feet so the players don't bump into the lines. On the whistle the first player skates forward up to the line and transitions backwards. Once that player hits the line and transitions backwards the player next in line (next to where the player is transitioning) skates forwards to the opposite blue line. This player is meant to be the "rabbit" for the player skating backwards. Players that are skating backwards should try to keep the other player in front of them. It is very challenging but it will force them to work on their speed going backwards.
A variation is to vary the distance between the two lines. In this animation it shows the lines at the blue lines, but it works well at other distances as well. For instance, for more conditioning, increase the distance so the lines are at opposite offensive zone face off dots. For quicker bursts place one line at the center ice and the other at the blue line.