Curt Miller was vocal about "the three Cs" when he was named head coach of the Connecticut Sun in 2015 — culture, chemistry and continuity.

Miller quickly changed the team chemistry and developed a winning culture.

The Sun ensured that Miller will be around to build continuity. The two parties agreed to a contract extension through the 2021 season that also includes an agreement with assistants Nicki Collen and Steve Smith.

Terms of the deal were not released. The franchise also extended his contract as general manager, a position added to his resume in 2016, through 2021. He was about to enter final year of a three-year deal.

“I’m really, really happy about the security that it gives us,” Miller said during a Tuesday conference call. “One of the things that was so important when I got here was a building sustained success and not just trying to put together a team that may have one year of success, and then you’re back to always rebuilding.

“Now, with this lengthy extension and commitment through the 2021, (it) allows us to get to work and continue to do it that way.”

Connecticut deftly handled an assortment of injuries and absences this season. It finished with the fourth best overall record in the WNBA (21-13), its first winning record since 2012. The Sun also qualified for the playoffs for the first time since that year.

Miller was named the 2017 WNBA Coach of the Year, as chosen by a media panel, and was selected by his peers as the inaugural winner of the Executive of the Year award. A media panel also voted Miller as the 2017 Associated Press Coach of the Year.

The Sun were 38-64 in the three seasons before Miller arrived. They’re 35-33 over two years with Miller, and 32-20 since July 2016.

“Curt is a masterful game planner who works tirelessly,” Sun vice president of sports Amber Cox said in a release. “He’s also done a tremendous job stepping into the general manager role, navigating through some adverse situations and ultimately guiding us back to the WNBA playoffs.

“All of Curt’s basketball prowess aside, what makes him special is his commitment to culture. The foundation of what he’s building on is based on belief, trust and compassion — for his players, his staff, our loyal fans, and this organization. He’s restored an energy to the Sun that’s palpable.”

n.griffen@theday.com