WASHINGTON — During a 5-2 Blues loss to the Capitals on Thursday night, it was pretty easy to pick out the difference in the game. Washington scored two power-play goals — and a third four seconds after a penalty ended. St. Louis went goalless in five chances on the power play. Just as special teams helped fuel the Blues in the last week, they handicapped their chances in Washington. T.J. Oshie had a hat trick for the Capitals, scoring both power-play goals and an empty-netter with 19.5 seconds remaining. Dylan Strome scored shortly after another power play in the third period, and Nicolas Aub…