5 storylines to watch in the NHL's 2nd half

The first half of the NHL season produced the unexpected rises of the Columbus Blue Jackets and the Minnesota Wild, a goal spree from Sidney Crosby, Connor McDavid leading the scoring race, strong starts for star rookies Auston Matthews and Patrik Laine, as well as a recent surge by Alex Ovechkin and the Washington Capitals.

Now that we're into the final 12 weeks, here are five storylines to follow as the league settles into its second half.

Calder Trophy chase

Laine and Matthews have received most of the attention and why not? Before a concussion sidelined Laine, the Winnipeg Jets rookie checked in with 21 goals and 37 points in 42 outings. Matthews has the same totals in 41 games for the Toronto Maple Leafs. Both have scored four game-winners.

But don't discount Columbus Blue Jackets defenceman Zach Werenski, Philadelphia Flyers blue-liner Ivan Provorov and Pittsburgh Penguins goalie Matt Murray.

The two defenceman have averaged more than 21 minutes a game. Provorov has been a pleasant surprise physically. Werenski has six goals and 26 points, approaching the numbers Florida Panthers defenceman Aaron Ekblad (12 goals, 39 points) put up when he won the Calder Trophy two years ago.

Murray, meanwhile, has gone 13-4-1 with a .925 save percentage, despite dealing with a couple of injuries. Steve Mason was the last goalie to win the Calder Trophy — in 2008-09, when he went 33-20-7 with a .916 save percentage.

Art Ross Trophy race

Can the remarkable McDavid hold on? The Edmonton Oilers' sophomore centre has a three-point gap over last year's winner, Patrick Kane of the Chicago Blackhawks, and a four-point advantage over Crosby and his teammate Evgeni Malkin.

If McDavid wins the Art Ross Trophy, his early NHL career path will be astonishingly similar to Wayne Gretzky's and Crosby's. Neither won the Calder Trophy nor the Art Ross in their rookie year, but they both won the scoring race in their second NHL seasons.

Gretzky and Crosby lost out on the Calder to Ray Bourque and Ovechkin, respectively. A broken collarbone cost McDavid the award last season, when it went to Chicago's Artemi Panarin. Gretzky matched Marcel Dionne's 137 points in the Great One's rookie year, but Dionne was given the Art Ross because he scored two more goals.

Canadian clubs

The Stanley Cup playoffs were contested without any of the seven Canadian teams last spring. As we enter the second half, Edmonton, the Calgary Flames, Montreal Canadiens and Toronto occupy playoff spots, while the Vancouver Canucks, Winnipeg Jets and Ottawa Senators are within striking distance.

Even though the Canucks and Jets are only two and four points, respectively, behind the Los Angeles Kings in the battle for the final playoff spot in the West, the two Canadian teams are in tough because the injury-riddled Kings and ninth-place Nashville Predators will be difficult to catch.

In the East, the Habs are a lock. Both the Maple Leafs and Senators are tied for third in the Atlantic Division for the final playoff spot with 48 points in 41 games, but Toronto holds the tiebreaker.

The provincial rivals trail the second-place Boston Bruins by three points, but the Senators and Maple Leafs each have five games in hand on Boston.

It may come down to either Toronto or Ottawa to claim the final playoff spot in the East. The Maple Leafs won the latest meeting, 4-2 in Ottawa on Saturday, and clash again in Toronto this Saturday.

Decline in Big D

Could the Dallas Stars, with all that talent, miss the playoffs? With 37 games remaining, the Stars are four points behind the Kings.

Dallas has been hit hard with injuries. Patrick Sharp, Jiri Hudler, Johnny Oduya, Cody Eakin, Jason Spezza, Jamie Benn and Alex Hemsky have all missed time with ailments.

But the Stars have so many holes in their game right now. Coach Lindy Ruff's team ranks 29th out of 30 in penalty killing and 26th in goals against.

Lightning doesn't strike

When the season began the Tampa Bay Lightning were considered one of the favourites in the East. Last spring, even with captain Steven Stamkos out due to a blood-clot issue, the Lightning managed to make it to the East final, a year after they visited the Stanley Cup final.

This season, Stamkos suffered a knee injury in mid-November, while goalie Ben Bishop, defenceman Anton Stralman and forward Nikita Kucherov also have spent time on the sidelines with injuries.

The biggest problem for Tampa has been preventing goals. The Lightning are 24th in goals against. There simply isn't much blue-line depth after Victor Hedman, Stralman and Braydon Coburn.

The Lightning have gone 1-5-0 in their past six games, and with Andrei Vasilevskiy in net yielded six goals each in losses to the Jets, Predators and Penguins.

Tampa bay is four points out of a playoff spot with 36 games remaining and today begins a critical six-game road trip.