Last week, Andre Stringer called his parents back home in Mississippi and told them the temperature was below zero in Portland. They didn’t believe him.

“I’ve never been anywhere as cold as it got those couple of days,” said Stringer, a reserve guard for the Maine Red Claws.

On Saturday night, inside the Portland Expo, Stringer found himself at the other end of the thermometer. He made six 3-pointers – including an improbable 34-footer that beat the shot clock – to lead Maine to a 111-100 victory over Santa Cruz.

Stringer finished with 23 points to become the eighth player to lead the Red Claws in scoring this season, which helps explain why Maine has the best record in the NBA Development League.

“We have a lot of good players on this team,” said Jermaine Taylor, who spent parts of the previous two seasons with the Red Claws and played in the only two playoff games in franchise history. “We don’t have to depend on one person. And we’re not selfish. So if Chris Babb gets hot, give Chris Babb the ball. If Dre (Andre Stringer) gets hot, we give Dre the ball. That’s how we are.”

To be sure, there is more to their success than generosity of spirit. As the Red Claws open play Thursday night as the top seed in the annual five-day D-League Showcase in Santa Cruz, California, here are the biggest reasons the team – after five seasons of mediocre basketball – is off to a 16-4 start:

Selfless play

Don’t just take Taylor’s word for it. The numbers bear out his assertion. A pass directly leads to a basket on 60.6 percent of Red Claws field goals. Only Santa Cruz sports a higher assist percentage.

In addition to Taylor, Babb and Stringer, the other five players with game-high point totals are point guard Tim Frazier, forwards Omari Johnson and Christian Watford, shooting guard James Young and post player Dwight Powell.

Young and Powell (since traded to Dallas in the Rajon Rondo deal) are NBA rookies who at times were on assignment from Maine’s affiliate, the Boston Celtics. The Red Claws went 4-0 with Powell in the lineup, and 7-1 with Young.

“We wish we could send more players up there,” said Danny Ainge, the Celtics’ general manager. “We play very close attention to what’s going on (in Portland). We watch to see how hard they play, how the team is executing. Watching them succeed is very much fun for us.”

Celtics’ attention

When Brad Stevens was hired as the Celtics’ coach in July 2013, his first priority in a rebuilding effort was in Boston. He then turned his attention to the Red Claws – along with Ainge, director of scouting Dave Lewin, director of player personnel Austin Ainge (a former Red Claws coach) and others within the organization.

They looked at the Red Claws not in the same way the Red Sox view the Sea Dogs – as a place to develop young players on their way to Boston – but mainly as an opportunity for talented rookies such as Young and Powell to get valuable experience under conditions that most simulate those with the Celtics.

“The single biggest reason why we spend money on the D-League,” said Lewin, who also serves at the Red Claws’ general manager, “is that a player such as James Young can go there, get playing time and get coaching that is in line with the Celtics’ coaching.”

Babb, one of three players (Taylor, Sherwood Brown) returning from last year’s roster, said the Celtics are much more involved with their D-League affiliate this season.

“We might have run one or two of their plays last year,” he said. “This year, basically 100 percent of our offense is the Celtics’.”

When the Celtics called him up late last season, Babb said he didn’t know many of their sets, play calls or out-of-bounds plays except a few he remembered from training camp.

“It was tough,” he said. “I feel like I was kind of out of rhythm offensively. This year, if anybody’s fortunate enough to be called up, I think it will be a pretty smooth transition.”

Shot selection

Lewin and Red Claws Coach Scott Morrison might be the only GM-coach pairing in the D-League with degrees in economics. Lewin also studied statistics and mathematics. Stevens is another proponent of statistical analysis.

Watch closely the next time the Red Claws play. You’ll hardly ever see them take a shot from just inside the 3-point line, or even a mid-range jumper. They love 3-pointers from the corner, particularly if the ball is kicked out after a dribbler has penetrated the lane.

Maine makes 37.2 percent of its 3-pointers, fifth in the league. Morrison digs deeper, however.

“When we shoot a 3 after getting in the paint, we’re shooting over 40 percent,” Morrison said. “When we don’t, we’re shooting around 20 percent.”

The rationale is simple. Defenses react when the ball gets closer to the basket.

“We bring everyone in and then we pass it out and we get wide-open shots,” said Taylor, who with Frazier is one of the team’s primary playmakers. “And on a team like this, everyone’s a shooter. If they don’t guard me or Tim getting to the hole, we’re going to get a layup. If they bring help in, we have guys like Chris Babb on the outside ready to knock down shots.”

Morrison also pays close attention to offensive rebounding percentage, free-throw attempt rate (field-goal attempts divided by free-throw attempts), assist-to-turnover ratio and turnover percentage. The Red Claws do well in assist-to-turnover ratio (1.49, third in the league) but are near the bottom in free-throw attempt rate (14th of 18) and offensive rebounding (14th). Their turnover ratio (15.7 per 100 possessions) ranks fourth, but they’re only forcing turnovers 15.1 percent of the time, which ranks 17th.

So there’s room for improvement.

Coaching

Both Danny Ainge and Lewin had high praise for Morrison and his staff, which includes assistants Nathaniel Mitchell and Seth Cooper. Similar to how the roster was built on players of character with work habits and attitudes to match – “We had a strict rule that we were only going to take guys we would be comfortable with any young Celtics player spending time with on or off the court,” Lewin said – the Celtics wanted everyone from the head coach to the interns to be hard-working, team-first guys who love teaching and development, both in the gym and watching video.

“We don’t have the most talented team in the D-League,” Lewin said. “That wasn’t our plan. What we do have are guys who want to defend, who share the ball, take good shots and work every day to improve.”

They’ve also upgraded the strength and conditioning program in Portland, going so far as sending Celtics assistant Ty Yeaton up from Boston several days a week to work with the Red Claws.

“I think they’re getting stronger and in better condition since they’ve been here,” Lewin said. “In years past they would lift, but the participation rate wasn’t quite as high. It was more on the Red Claws and their trainer. They did the best they could but it wasn’t a point of emphasis.”

If history is any guide, few of the Red Claws will wind up playing for the Celtics. Of the eight players signed from the Red Claws to an NBA club, only Babb went to Boston. So opportunities may lie elsewhere, if not in the NBA, then with some well-paying gig overseas.

“We want our guys to get called up, obviously with the Celtics, but anywhere,” Lewin said. “We’re just happy for these guys to have success because they’ve worked hard and they’ve earned it.”