North Point boys’ basketball Coach Jimmy Ball: “People moved from D.C. to P.G. and now people from P.G. are moving to Southern Maryland. It’s a chain reaction.” (John McDonnell/THE WASHINGTON POST)

Shirley Davis-Wright was born in the District and lived in Prince George’s County for more than three decades before she decided to look for a quieter place to raise her only son eight years ago. A friend suggested she look south to Charles County, but Davis-Wright was skeptical of what she considered to be a remote location.

“I went and looked, but I had no plans to actually move there,” Davis-Wright said. “You heard people say they were moving to Waldorf and I’d be like ‘Ew, really?’ But then I saw these really nice four-level townhouses and we moved.”

From 2000 to 2010, the population of Waldorf, in northern Charles County, tripled. And many of the new residents are, like Davis-Wright, from Prince George’s. The migration appears to have had a distinct impact on the basketball fortunes of teams from the Southern Maryland Athletic Conference.

Long considered inferior to their counterparts from Prince George’s and around the state, the SMAC has five teams playing in the state semifinals starting Thursday at Comcast Center (boys) and Maryland-Baltimore County (girls). Among them is defending 4A champion North Point (23-2), which opened in 2005 and last year became the first boys’ basketball team from the SMAC to win a state title since 1972. Also back to defend their 2A title are the No. 9 Calvert girls (24-1), which in 2011 became the first Calvert County basketball team — boys or girls — to win a state championship.

“When we were growing up, teams from Prince George’s County couldn’t wait to play Charles County teams,” said North Point boys’ Coach Jimmy Ball, who graduated from La Plata High in 1986. “It’s a little bit different [now], but I still think P.G. teams look at us and they want to play a Charles County team or a team from Southern Maryland. Yeah, we’re holding our own a little bit, but that’s the way it goes.”

Ball readily admits to relishing the role of the underdog, but the days of such motivational speeches might be coming to an end. His team went 27-0 last year and led by Davis-Wright’s son, standout junior point guard Marquis Wright, this season’s team is a threat to repeat; the No. 7 Eagles play 12th-ranked Eleanor Roosevelt of Prince George’s in the semifinals.

In the Maryland 3A semifinals Thursday, ninth-ranked Thomas Stone, also located in Waldorf, plays Centennial. Meantime, on the girls’ side at UMBC, on Thursday seventh-ranked North Point plays sixth-ranked Wise in the 4A semifinals and 20th-ranked Westlake (also located in Waldorf) plays 18th-ranked River Hill in the 3A semifinals. Calvert plays Patterson Mill in Friday’s 2A semifinals.

“Years ago we were small counties,” Calvert girls’ Coach Frank Moore said. “With all the people moving in the last 15, 20 years, I don’t know if that has something to do with [the success], but I’m sure it helps.”

Some attribute the shift in power to the growth of travel teams in Southern Maryland, giving players the opportunity to work on their games throughout the year. That, coupled with relaxed restrictions on out-of-season practice, seems to have spurred high school coaches to put in more time year-round.

Also, compared with jurisdictions closer to the District, there is a lack of private schools with elite basketball teams. In the three Southern Maryland counties — Charles, Calvert and St. Mary’s — St. Mary’s Ryken in Leonardtown is the only private school competing in an elite league (the WCAC), though some residents choose to make long commutes to play for other top programs.

“They start building some private schools in Waldorf, you’ll start seeing a difference,” said Douglass boys’ Coach Tyrone Massenburg, who has coached in Prince George’s for 25 years.

“We’re not as strong as we used to be,” said Prince George’s Director of Athletics Earl Hawkins, who played at Gwynn Park and later coached at Douglass and Crossland.

Many players who might have helped Prince George’s teams now lead Southern Maryland squads, including Wright, a junior floor leader who hopes to earn a college scholarship.

“There is a lot more people moving down and living in our area, [so] of course you are going to get some kids that are a little bit more talented than what were there before,” Ball said. “That’s a benefit. It helps overall in all our programs, not just at North Point. All over. People moved from D.C. to P.G. and now people from P.G. are moving to Southern Maryland. It’s a chain reaction.”