WASHINGTON — The Sky once again found themselves in the all-too-familiar position of trailing their opponent Sunday.
This time, it was the Mystics with a six-point advantage heading into the fourth quarter. Despite emphasizing their need to apply what they’ve learned from their inability to overcome deficits all season, the Sky again were unable to execute a comeback.
Their 83-76 loss to the Mystics dropped them to 12-18 and into a tie with the Sparks for the eighth and final WNBA playoff spot. The Mystics, meanwhile, opened a two-game advantage over those teams for the seventh spot.
‘‘We weren’t prepared well, and that is my responsibility,’’ interim coach/general manager Emre Vatansever said. ‘‘I take ownership of that. I could have prepared them well, and I didn’t.’’
After the Mystics’ lead grew to 12 with five minutes left, Sky star Kahleah Copper got hot. She made back-to-back three-pointers to cut the Mystics’ lead to six and force them to call a timeout.
The Sky forced a turnover out of the break, with the Mystics’ Brittney Sykes falling out of bounds. After the whistle was blown and with Sykes lying on her back, the Sky’s Marina Mabrey tried to tie up the ball. After an official review, Mabrey was assessed a technical foul, and Sykes proceeded to make the free throw.
‘‘No,’’ Vatansever said in response to a question about whether that moment took any of the Sky’s momentum. ‘‘We took our momentum.’’
Copper struggled on the Sky’s two-game road trip. After scoring more than 20 points in four consecutive games, she combined for 25 in the Sky’s back-to-back losses to the Liberty and Mystics. She scored 11 of her 17 points Sunday in the fourth quarter.
In both games, Copper got into foul trouble early and was on the bench for an extended period.
Mabrey added 15 points, Elizabeth Williams 14 points and a season-high 12 rebounds, Courtney Williams 13 points and seven assists and Alanna Smith 10 points for the Sky, who put all five starters in double figures but were outscored 23-7 off the bench.
‘‘They’re professional players,’’ Vatansever said of his bench. ‘‘They need to play.’’
Sykes went off for the Mystics, finishing with 30 points on 11-for-18 shooting. She scored 13 in the third quarter to help stop a run that had pulled the Sky into a 45-45 tie with six minutes left in the quarter.
On top of a season-high scoring night, Sykes helped lead the Mystics’ unrelenting defensive attack. They forced 17 Sky turnovers, which they converted into 20 points.
With 10 games remaining — four of them against the top three teams in the league — the Sky are running out of time to make the necessary adjustments to secure their fifth consecutive postseason appearance.
‘‘We’re disappointed that we lost this one because we could have put ourselves in a much better position,’’ Elizabeth Williams said. ‘‘Fortunately, there are 10 games left, and one of them is against the Sparks. We’re in control of our own destiny at this point. We’re not hoping that other teams lose. That’s really the message.’’