Mystics Coach-General Manager Mike Thibault has won the most games in WNBA history. (Katherine Frey/The Washington Post)

Washington Mystics Coach-General Manager Mike Thibault has signed a four-year contract extension, the team announced Wednesday afternoon before departing on a three-game road trip over eight days. Terms of the deal were not disclosed.

Thibault took over the Mystics on Dec. 18, 2012, and directed them to the playoffs in his first three seasons. Washington had won 11 games combined over the two years before Thibault’s arrival.

After the Mystics missed the playoffs last year for the first time under Thibault, he engineered the most significant move in team history by adding Elena Delle Donne. Thibault traded the No. 2 overall pick this year, center Stefanie Dolson and guard Kahleah Copper in exchange for the 2015 WNBA MVP.

“It is an exciting time to be a Mystics player, coach, staff member or fan,” Thibault said in a statement. “It has been a total rebuilding process that is coming to fruition, and I am looking forward to the many great years ahead with this excellent core group of players that we have been able to put together.”

Thibault also signed point guard Kristi Toliver as a free agent. Toliver spent the previous seven seasons with the Los Angeles Sparks, with whom she won the WNBA Finals last year. The native of Harrisonburg, Va., was a starting guard on Maryland’s national championship team in 2006.

During his first season with the Mystics, Thibault became the winningest coach in league history.

Before coming to the District, Thibault coached the Connecticut Sun for 10 years, including consecutive trips to the WNBA Finals. The Sun has not made the playoffs since parting ways with Thibault following the 2012 season.

“Mike is one of the best in the game, and we are thrilled that he will continue to lead this franchise,” Ted Leonsis, the founder and chief executive of Monumental Sports and Entertainment, said in a statement. “He is the winningest coach in WNBA history and has put together an impressive team that is both a fan favorite and built to succeed.  We look forward to his continued leadership.”