Everyone has different criteria for report card grades and brings different priorities to the debate. Thus, before evaluating the San Jose Sharks in the early third-plus of the 2013 season, it is important to define the report card parameters.
Anyone can say San Jose is 25th in goals scored per game (25th percentile) and grade them accordingly. Some even try to act like special teams compare to offense and defense like it does in the NFL.
It is power play, penalty kill and even strength. (It is also a sweater not a jersey, and a dressing room not a locker room.) That is because the team's power play is part of the offense, and the team's penalty kill is part of the team's defense.
If you give up four goals because your penalty kill gives up three, you do not have a bad defense and a bad penalty kill. The defense was good until it went on the penalty kill, establishing that the correct comparison is between PK and even strength.
While the PK is elevated too high, other elements of a defense are scarcely made known. Most NHL fans only know where teams stand that are very good or bad at blocked shots faceoffs, takeaways or giveaways—collectively called "real-time stats" on NHL.com.
It is in those details that the picture of what a team is doing on the scoreboard comes more into focus. Grades based on these statistics means they can be objective, though variables must still be considered—i.e. a team that controls the puck will have fewer chances at blocks, etc.
Note that there is no slide for hits, an overrated stat because it is assigned at the discretion of home statisticians. Some assign them more liberally than others, particularly to their own team.