The Capitals have seven defensemen ─ not including an injured Tom Poti ─ ready to compete for ice time this season. That means there will be plenty of speculation as to what the blue-line pairings will be.

 John Carlson and Karl Alzner, a right-handed/left-handed combination, played together for much of last season. Both of them played strong, steady defense and, when on the ice together, routinely shut down the opposition's best talent.

 Assuming they can repeat their success from last year, there is no reason why Carlzner shouldn’t make up the Caps' top defensive pairing for a second straight season.

 Two-time Norris finalist Mike Green, who missed 33 regular season games last year due to injuries, ought to anchor the second pairing along with newly-acquired defenseman Roman Hamrlik.

 “You’ll have to see them play together to see how they mesh," Coach Bruce Boudreau said after the Capitals signed Hamrlik on the first day of free agency. "I mean, right now it sounds like a really good combination, Green and Hamrlik, but only time will tell.”

 But why wait when we’ve got fancy stats to give us an answer now?

 Hamrlik is a three-time NHL all star with a solid two-way presence. He finished second in points, first in blocked shots and third in time on ice per game among Montreal's blueliners last season.

Spacek employs a more traditional, stay-at-home style of defensive play while Wisniewski, who tied for fifth among NHL blueliners in points during the 2010-11 season, is an offensive defenseman similar in style to Green.

Wisniewski was also much improved, showing that Hamrlik's age and experience could augment Green's skating and puck-handling ability.

“I think hockey wise, I stay back and try to play better defense and I know P.K. [Subban] or Mike [Green], they can enjoy better offense and they have a chance to create something,” Hamrlik said last month.

A Green-Hamrlik pairing will definitely create some scoring chances, and perhaps create a chance to win in the playoffs as well.

Neil Greenberg also writes for Russian Machine Never Breaks. Follow him on Twitter: @ngreenberg.