Sixteen storylines to watch as training camps begin

The ice is down, the skates are sharpened and NHL players are starting to report to training camp. They'll have to hit the ice on the fly; preseason games start Sunday, and the regular season begins Oct. 7.

Here are 16 storylines to watch as the 30 teams head to training camp:

First look at 3-on-3 overtime: The new OT format, implemented to reduce the number of games decided by a shootout, will get an extended test during the preseason. A total of 45 games (regardless of whether they are tied after regulation) have been designated for mandatory 3-on-3 sudden-death overtime, although games that weren't tied at the end of regulation won't go to a shootout if no one scores in the five-minute extra period. These games will give teams the chance to test out the new format before the regular season begins.

McDavid arrives in Edmonton: Connor McDavid, the first player taken in the 2015 NHL Draft, is a center who's regarded as a generational talent and is expected to spark a revival of the Edmonton Oilers, who haven't made the Stanley Cup Playoffs since 2006. McDavid gave his new team a taste of what he can do when he had three assists Wednesday in a rookie game against the University of Alberta. New coach Todd McLellan will spend a lot of time in camp figuring out how McDavid fits in best, who will play with him, and how to keep expectations from soaring out of sight.

Eichel comes to Buffalo: Jack Eichel, also a center, led the NCAA in scoring at Boston University last season; he was the second player taken in the draft and joins an overhauled Buffalo Sabres team that was last in the NHL in scoring in each of the past two seasons. New coach Dan Bylsma faces many of the same challenges with Eichel as McLellan does with McDavid; he'll have to figure out who to play with his star rookie and keep expectations from going overboard.

Defending champions revamp roster: The Chicago Blackhawks will try to become the first team since the Detroit Red Wings in 1997 and '98 to repeat as Stanley Cup champions, but they'll enter camp with the task of integrating a number of new players into the lineup. Four key forwards, Brandon Saad, Patrick Sharp, Kris Versteeg and Brad Richards, are gone, as is top-four defenseman Johnny Oduya. Coach Joel Quenneville faces the task of working in veteran newcomers like defenseman Trevor Daley and forward Artem Anisimov as well as talented young players such as forward Marko Dano into a group that won it all three months ago.

Lightning strike: The Tampa Bay Lightning came up two wins short of the second Stanley Cup in franchise history last season, losing the Final to the Blackhawks in six games. They come to camp with arguably the most balanced roster in the Eastern Conference, led by forwards Steven Stamkos and Tyler Johnson, defenseman Victor Hedman and goaltender Ben Bishop. But Johnson is coming off a wrist injury, and Stamkos is entering the final season of his contract. Coach Jon Cooper's biggest challenge as camp begins is to make sure there's no hangover from the loss to the Blackhawks; since 1984, only the 2009 Pittsburgh Penguins have come back after losing the Final to win the Cup the following year.

Babcock heads to Toronto: Mike Babcock never missed the playoffs during a successful decade as coach of the Detroit Red Wings. He signed an eight-year contract with the Toronto Maple Leafs in May that made him the highest-paid coach in NHL history, but getting a rebuilding team to the postseason right away may be more of a challenge than even he can overcome. Babcock enters camp having to deal with the usual "getting to know you" problems faced by any new coach as well as the pressure to succeed in Toronto; the Maple Leafs have made the playoffs once since 2004.

New coach in Detroit: Babcock's departure opened the door for the Detroit Red Wings to hire Jeff Blashill, who enjoyed great success running the Grand Rapids Griffins, their affiliate in the American Hockey League, for the past three seasons. Many of the players he coached with Grand Rapids are now in Detroit, where Blashill also spent a season as an assistant under Babcock. Blashill will benefit from working for one of the NHL's best management teams and a solid base of young talent; his biggest task in the early going will be to establish his own identity.

First-timer in Philadelphia: The Philadelphia Flyers went off the grid when they passed on a number of better-known candidates and hired Dave Hakstol as the 19th coach in franchise history, replacing Craig Berube. Hakstol, who spent the past 11 seasons coaching the University of North Dakota, is the first man since Bob Johnson in 1982 to go directly from the NCAA to the NHL. It's an out-of-the-box move by general manager Ron Hextall, who knew Hakstol because his son Brett played for him at North Dakota. Hakstol ran an elite college program, but taking command of an NHL team trying to get back into the playoffs figures to be a big challenge for someone with no NHL experience.

Finding a fit for Kessel: The Pittsburgh Penguins brought in forward Phil Kessel, a five-time 30-goal scorer, from Toronto in an effort to jumpstart an offense that ran out of gas last season. Coach Mike Johnston said he plans to start camp with Kessel playing right wing on a line with Sidney Crosby; if that combination doesn't work, he can try Kessel with his other star center, Evgeni Malkin. Integrating Kessel quickly is a must for the Penguins, who scored one goal in each of their four losses to the New York Rangers in their Eastern Conference First Round series in April.

Lots to "C": The Montreal Canadiens have two areas of intrigue. After three seasons as a wing, Alex Galchenyuk is being moved to center in hopes he can provide the kind of strength and speed down the middle that have been missing. More interesting is general manager Marc Bergevin has promised to name a captain before the start of the season after going without one in 2014-15. It's likely that one of the four players who served as alternates last season (Max Pacioretty, Tomas Plekanec, P.K. Subban and Andrei Markov) will trade his "A" for a "C."

Retool or rebuild: The Boston Bruins' failure to qualify for the playoffs last season cost general manager Peter Chiarelli (now in Edmonton) his job. New GM Don Sweeney made headlines in June by trading away defenseman Dougie Hamilton and power forward Milan Lucic, mostly for draft picks. Two years after coming to camp following a trip to the Final, the Bruins will take the ice this weekend unsure of whether they're coming off a one-year hiccup or entering the start of a rebuilding period.

Flames burning brightly: Hamilton's arrival and the return of captain Mark Giordano from injury gives the Calgary Flames perhaps the NHL's best six-man defensive unit and should help them take the next step forward. Despite being one of the NHL's poorest possession teams last season, Calgary was one of the League's surprises; the Flames qualified for the playoffs for the first time since 2009 and won a round for the first time since 2004. Coach Bob Hartley undoubtedly will spend much of training camp reminding his team the accomplishments of last season don't carry over, and that moving into the NHL's elite won't be easy.

Brooklyn-bound: After 43 years at the Nassau Coliseum, the New York Islanders will play their home games at the Barclays Center in Brooklyn, beginning with their preseason opener Monday. Their new home is much more palatial, but will the home-ice advantage they enjoyed at the Coliseum last season make the trip to Brooklyn? The Islanders are coming off their most successful regular season since their dynasty days of the early 1980s. Getting used to a new home is vital for a team that plays 10 of its first 15 regular-season games in Brooklyn.

Dubnyk's challenge: The Minnesota Wild acquired goaltender Devan Dubnyk from the Arizona Coyotes on Jan. 14, and he carried them all the way to the second round of the playoffs with one of the best half-seasons by a goaltender in recent NHL history (27-9-2, 1.78 goals-against average, .936 save percentage). That earned the 29-year-old journeyman a six-year contract, but he enters camp facing the question of whether he can even come close to matching that performance or whether his heroics last season were a one-off.

Ducks goalie battle: The Anaheim Ducks have the talent, size and speed to be favored to win their fourth straight Pacific Division title, regardless of who's in goal. Frederik Andersen had an excellent regular season in 2014-15 while John Gibson missed much of it with injuries and ended up as a backup. But Andersen couldn't close the deal in the Western Conference Final after the Ducks took a 3-2 series lead against the Chicago Blackhawks, losing Games 6 and 7. Gibson is healthy and will come to camp trying to prove he's ready to grab the starting job on a team with serious Cup aspirations. Complicating matters, veteran Anton Khudobin was added to the mix during the summer.

Friendly rivalry: Dallas Stars goaltenders Kari Lehtonen and Antti Niemi shared time in goal for Finland at the 2014 Sochi Olympics. They'll do the same with Dallas after the Stars acquired Niemi from the San Jose Sharks and signed him to a three-year contract. Lehtonen is the incumbent, but he's coming off a season in which he had a 2.94 goals-against average and a career-worst .903 save percentage. Niemi (2.59 GAA, .914 save percentage with San Jose) will provide the kind of challenge Lehtonen hasn't faced in years. The stakes are high; the Stars have one of the NHL's most dynamic offenses but need improved goaltending to return to the playoffs.