WATERVILLE — To most observers, the game of hockey breaks down into a few statistical categories.

Shots. Saves. Power plays. Penalty kills. Get a little crazy, and you can throw in things like blocked shots, face-off wins and losses, and even Grade A scoring chances.

In the end, though, one of the most crucial — and often overlooked — parts of the game of hockey are zone entries and zone exits.

A team’s ability to get the puck out of its zone cleanly, and into the attacking zone just as seamlessly, is critical to its overall success. Entries and exits, when done efficiently, make all of the other statistical analysis nearly irrelevant.

“Zone entries are absolutely huge,” Hampden Academy coach Eric MacDonald said. “We work on it every day in practice, getting pucks out of the zone and working pucks deep. We work on it every single day and work extremely hard on it. Some days we’re good, some days we’re not, but we try to get better at them every day.”

In a Class B North boys hockey doubleheader Saturday at Alfond Rink, those exits and entries dictated the outcomes of games.

To wit: In its 4-2 win over Waterville/Winslow, Hampden Academy looked unbeatable (the Broncos are 7-0-2 this season) when cleanly moving the puck from zone to zone and rather pedestrian when they did not. Messalonskee scored a 6-3 win over John Bapst because they recovered from a sloppy second period to clean things up in the third.

Be it a two-on-one rush the other way or a turnover behind your own net which turns into a one-time goal for the opposition, those moments can almost always be traced to an inability to enter or exit any of the three zones on the ice.

“Transition game play we work on a lot,” Messalonskee coach Kevin Castner said. “Those are critical moments in the game. We let the guys know we can’t have turnovers in certain areas of the ice, and we need to get our heads up and move the puck to areas of the ice where we have space.”

Entries and exits aren’t any more or less significant during special teams situations.

Hampden had plenty of opportunities with the power play in the second period against the Kennebec RiverHawks to extend its lead — but the team’s first three power plays only produced four shots after Kennebec routinely stymied the Broncos’ ability to enter the offensive zone with either speed or possession.

When a team can’t gain the offensive blue line, it can’t set up its power play. And that can make for a very frustrating night.

“It’s so important to get the puck in the zone, set it up, work it around,” MacDonald said. “And it’s equally important on the defensive side (killing penalties). You can’t let teams set up on you. You’ve got to get pucks deep and get pucks out.”

Messalonskee’s nightcap victory was nearly a carbon copy of Hampden’s.

Up 4-1 early in the second period, the Eagles (6-2-1) took their foot off the gas. It led to a lot of extended zone time for John Bapst, and an inability for Messalonskee to relieve pressure. There simply weren’t enough simple plays to be made.

No exits, as it were.

“You can always move the puck more,” Messalonskee senior defenseman Sean Rodrigue said. “You can play it high off the glass more, make more safe plays.”

But by the time the third period had rolled around, Messalonskee looked much more like its dynamic offensive self. It all derived from an ability to exit the Eagles’ zone cleanly and then enter the Crusader zone with both speed and puck possession.

In those moments, hockey games are decided.

“On the defensive side, we want to take away space,” Castner said. “On the offensive side, we want to create space. With transition, those are the moments we can actually use to create that time and space.”