New York Islanders center John Tavares reacts as time runs...

New York Islanders center John Tavares reacts as time runs out against San Jose Sharks during the third period of an NHL hockey game at Barclays Center on Tuesday, Oct. 18, 2016. The Sharks defeated the Islanders 3-2. Credit: Kathleen Malone-Van Dyke

They are five games that have essentially doomed the Islanders season not even a quarter of the way through. Five late-game regulation losses, including back to back in the last two stops of this past week’s California road trip, that have the Islanders in must-win mode before we’ve even reached December.

Forget that, actually: It’s must-run-off-six-straight-wins mode for the 30th-place Isles to even think about the playoffs.

“I’ve never been on a team that’s had this happen,” said Jason Chimera, who was on some lousy Oilers and Blue Jackets teams during his 16-year career. “I’ve never seen anything like this.”

Chimera said this on Thursday, before the latest and most wrenching loss to the Sharks. Is there a theme, a common thread to the five enormous letdowns? Here’s a snapshot of those losses and the plays that led to them:

n Oct. 18 vs. San Jose. In a very evenly played 2-2 game the Sharks enter the Isles zone and set up three across the blue line. Joe Thornton collects a pass along the boards near the blue line, turns and sends the puck into the soft space in the high slot where Joe Pavelski pops out and beats Nick Leddy to the spot to redirect the puck past Jaroslav Halak at 17:50.

n Oct. 26 vs. Montreal. Shea Weber’s power-play cannon at 17:03 decides it (and nearly takes off Travis Hamonic’s face in the process), but the mess the Isles made in the defensive zone after Josh Bailey’s turnover in the Canadiens end leads to Nick Leddy’s hooking penalty. Leddy was caught up the ice, Bailey and Anthony Beauvillier tried to cover deep in the Isles end and Brendan Gallagher emerged in front of Thomas Greiss despite four Islanders trying to defend two Canadiens. Leddy hooked him, and the Isles were doomed.

n Oct. 27 at Pittsburgh. Sidney Crosby’s borderline interference on Johnny Boychuk was most memorable in the sequence leading to Crosby’s winner at 17:35, but Thomas Hickey had possession after Crosby picked off Boychuk. Hickey sent a pass up the wall to Shane Prince but he was quickly dispossessed by Justin Schultz and Scott Wilson swept the puck towards the net, where Crosby jammed it past Halak.

n Wednesday at Los Angeles. Similar to the Canadiens loss, the Islanders had numbers in the defensive zone with just under five minutes to go and Leddy ended up in the box after denying a chance in tight. Chimera, John Tavares and Beauvillier were all near the blue line when Jake Muzzin stopped a clearing attempt and Jeff Carter whipped a pass through those three and behind Leddy and Hamonic for Tyler Toffoli, leading to the penalty call. Dwight King’s double-deflected goal at 17:07, one second after the power play ended, did the Isles in.

n Friday at San Jose. The Islanders had the personnel they wanted on the ice to preserve the just-tied game: Nikolay Kulemin, Cal Clutterbuck, Casey Cizikas, Calvin de Haan and Adam Pelech. De Haan and Pelech had Pavelski and Patrick Marleau pinned behind the net, but the two veteran Sharks won the puck battle, Thornton fed David Schlemko who fed Brent Burns and Marleau beat Clutterbuck to the high slot for the redirect at 19:37.

Jack Capuano cited the hockey gods after Friday’s loss, but that’s a coach trying not to single anyone out. There are too many different Islanders on the ice for these goals to really assign blame, too many different situations to say there’s one reason why the Islanders keep blowing these games.

Barring a miraculous turnaround, these will be the five games that sent the Islanders to the draft lottery.

Berube’s book club

J-F Berube still hasn’t played a game this season and spends all his practice days getting half the reps of a regular NHL goaltender, having to share a net with either Halak or Greiss.

So there’s a need to stay sharp without the physical work. Enter Berube’s book choices the last few months.

He’s read “The Champion’s Mind,” by sports psychologist Jim Afremow, and “Talent is Overrated: What Really Separates World-Class Athletes From Everybody Else,” by Geoff Colvin.

“Without being in games, you have to try to keep focused and prepared any way you can,” Berube said.