Imagine being under .500 and facing down a 19-11 team that you lost to by 10 points a week ago. Their leading scorer is out with an injury — but so is yours. You’re trying to beat a team that’s won six straight, while you’ve gone 2-4. If you’re the Washington Mystics, you just did that with a 78-67 victory Thursday over the visiting Seattle Storm. Mystics’ leading scorer Alana Beard — who watched…