The New York Islanders entered the 2017-18 season with an open spot on defense — and the contest for ice-time has no clear winner.

From the start of the 2017-18 season, the departure of Travis Hamonic signaled a shift along the Islanders’ blueline.

Each of Adam Pelech, Scott Mayfield, and Ryan Pulock’s career games played totals less than a season’s worth, and all three are in the thick of a battle for playing time.

Throw in Calvin de Haan, who needs to prove himself if he wants another contract from General Manager Garth Snow this coming offseason, along with the struggling veterans in Dennis Seidenberg and Thomas Hickey, and the blueline starts to get more than crowded.

With the pending contract status of de Haan and Hickey for the 2018-19 season, and the unlikelihood that the Islanders turn to Seidenberg’s services after his deal expires, the bulk of the competition is being fought out by three kids the Islanders want to retain long-term.

Taking a look at the rookies through the first 17 games of the season, here’s how they individually break down:

Adam Pelech

The 2016-17 season was Pelech’s first NHL season, and although the Toronto native played in only 44 of the club’s games, the sample size was large enough to warrant a four-year extension from Snow.

Having played in 13 games, Pelech has five points and the team’s second-highest +/- rating at seven (de Haan leads the team with eight).

The 23-year-old has already taken large strides in understanding the NHL and is noted for an effective, hard-checking game particularly along the boards. His physical presence is by far his most improved aspect thanks to a bolstered confidence that grows in every game.

Scott Mayfield

NEW YORK, NY – OCTOBER 24: Scott Mayfield #42 of the New York Islanders celebrates his goal at 17:03 of the third period against the Arizona Coyotes the Barclays Center on October 24, 2017 in the Brooklyn borough of New York City. The Islanders defeated the Coyotes 5-3. (Photo by Bruce Bennett/Getty Images)

By far the most improved rookie, Mayfield went from the status of being a questionable spare part to an integral cog in the Islanders’ top-four pairings.

It’s not hard to pinpoint what Mayfield has been able to do — his 6′ 4″, 227-pound frame has been able to keep him firmly on the puck. Possession is the first step in helping a team generate offense, and that’s been the key in Mayfield’s game.

It’s best summarized in his goal against the Colorado Avalanche, not giving up on the play and strong-arming himself into ideal positions.

A brief injury stint kept him off the roster for a short amount of time, but aside from that Mayfield is leading the pack of hopeful defensemen.

Ryan Pulock

With the way that both the Islanders and Pulock finished last season, there’s no way he isn’t a lock on this team heading into the season — right?

We were all thinking the same thing before puck drop on October sixth. Fast-forward to now, and Pulock has actually played the fewest games of the crop of youth this season. That’s not to say Pulock has played poorly — but arguably the most promising of the trio has shown some struggles.

When he initially slotted into the lineup, Pulock immediately tallied the Islanders’ first powerplay goal of the season, assisting on Anders Lee’s goal.

It hasn’t come easy for Pulock, who didn’t really settle back into the NHL until around his third or so game. Since then, Pulock has shown more improvement playing in the defensive zone, which was one of the big reasons why he had wasn’t called up last season.

Pulock’s strengths are highlighted when the Islanders gain zone time. His cannon of a shot is still taking time to settle in, but his offensive awareness has been on display in his later showings. Obviously, to grow into his role he needs playing time. But with the level of competition for playing time, it’s unclear if he’ll be able to sustain a presence in the lineup.

That is entirely up to his preparedness.

The only thing that has been made clear so far is that this competition has promoted the ability to get the best out of these players and that it only ends after one or multiple players are moved.