The Blackhawks’ 2013 success has been paved by a complete-team effort. Forwards’ improved defense has helped the team to a league-best plus-36 goal differential this season. And the defensemen? Well, they’re adding to those point totals. Blackhawks defensemen have been contributing offensively this season. Nick Leddy and Brent Seabrook were the latest when they added their fifth and sixth goals of the season, respectively, in the team’s 2-0 victory over Calgary on Tuesday. The blue-line contributions have benefitted the Blackhawks, who have done well spreading the scoring wealth. “Our D has been good in contributing to our offense, be it off the rush or the zone,” coach Joel Quenneville said. “We definitely have some good shooters on the back end. We definitely have some motion going in the offensive zone, which can be tough to contain defensively. They don’t stay stationary. They’re looking for direct plays and getting involved with our cycle game, which enhances our puck possession game.”