The 1" Running Pliers from Diamond Tech help you run a score along glass and break glass pieces with minimum effort.
 
Pro Tips:
Simply position the jaws of these durable metal pliers at the end of your score on the edge of the glass, make sure the centering mark is facing up and lined up with the score line. Then gently squeeze for a clean break. If you have a long score start running the score from one side and then run it from the other side until they meet.
The screw on the running pliers allows you to adjust the pliers to the thickness of the glass you are cutting. Before cutting set the running pliers onto your glass and gently close them. Tighten the screw all the way down, then back it off about half a turn. This will allow the pliers to close just a little bit smaller than the thickness of your glass, which will help you make a clean break.