Hard-core high-school basketball fans should be in their glory this week as the field of potential heirs to the throne narrows with every game.The Lynnfield and Winthrop boys basketball teams will square off tonight in the Division 4 North semifinals at Lynn Classical. Game time is 7 p.m.In one corner will be the Pioneers, a team that finished 5-15 a year ago and that, until this year, hadn’t qualified for the state tournament since the 2001-02 season. In the other corner will be Winthrop. Under coach David Brown of Lynn, the Vikings have racked up their most wins (14) since 1995.Lynnfield is coming off a dizzying 91-83 overtime win against Trinity Catholic over the weekend, the highlight being a 58-point performance by senior guard Mike Kennedy. The Vikings survived the quarterfinal purge with a 62-47 win over New Mission. Winthrop dug itself into an early hole, trailing by 16 points in the first quarter before storming back to win the game.Lynnfield coach Scott McKenzie has relished the role of the underdog throughout the tournament and he expects the label to carry into tonight’s game despite Kennedy’s heroics the other night. Winthrop limped to the finish line, literally, at the end of the season with one of its big guns, John Murdock, sidelined with a sprained ankle. Murdock is back and, according to Brown, feeling better all the time.The Vikings’ strategy is pretty clear-cut. They have to stop Kennedy, or at least keep him from doing too much damage. Brown got his first look at Kennedy against Trinity, and let’s just say he was impressed.”We’ll have our job cut out trying to contain Kennedy. He plays every possession like it’s his last possession,” Brown said. “He’s lightning-quick. He shoots the ball very well and he’s a great passer.”Brown said he was impressed by Kennedy’s ability to get into the lane, create fouls and create opportunities for himself and other players. Brown is hoping to keep him in the 20s.McKenzie and crew are facing a Winthrop team that tunes up for the tournament against some pretty stiff competition – Classical, English, Salem, Swampscott, Beverly, and Marblehead – just to name a few of the Vikings’ Northeastern Conference foes.The Vikings will come at the Pioneers with a multifaceted scoring attack. Dino Mallios leads Winthrop with 17 points per game, and the 230-pound Murdock is good for about 11 points and eight rebounds a night. Mike Visco, the Vikings’ other big man, is averaging eight points and nine rebounds per game.With Murdock on the sidelines the final four games of the season, other Winthrop players have had to step it up and fill the void. One of the players who answered the call was Mark Jenkins. Jenkins averaged 15 points per game over the last five regular-season games.Point guard Gavin Mahoney (8 points, 5 assists, 1 turnover per game) runs the Viking offense and does a great job taking care of the basketball, Brown said.The Vikings’ fifth starter, Ken Quist, will be on Kennedy initially. Quist played cornerback for the football team in the fall and is a “strong, quick kid with good anticipation,” Brown said. “He’s not going to wear him (Kennedy) down. That kid can run forever. But he’s going to make him earn every basket he gets.”This is the furthest a Winthrop team has been in three years. The Vikings finished 12-8 during the regular season, but they were 12-4 before Murdock got hurt.”They (Lynnfield) like to push the ball. We like to push the ball in transition. I’m expecting a high-scoring affair,” Brown said.Although the game is at a neutral site, Brown is hoping to draw a few fans from his hometown. He played basketball at St. Mary’s and was an assistant coach for the Spartans under former coach Parker Livermore before taking the Winthrop job.”I should have a lot of friends and family here,” Brown said. “I’m hoping to get some support from some local people.”Although those on the outside looking in at the Lynnfield program are probably amazed at what Kennedy has accomplish