Tyler Moore is proving to be a valuable weapon for Washington. The rookie out of Mississippi State belted a tape-measure three-run homer on Tuesday night, helping the first-place Nationals pound Colorado 12-5 at Coors Field. Moore, a right-handed hitter who can play first base or the outfield, now has three big-league homers in 47 at-bats. He is also hitting .319 with eight RBIs and seven runs in 22 games as a part-time player. Moore’s power is no fluke: He has hit 71 homers in his last three minor league seasons, including nine in Triple-A this year. P.S. Former Jackson Mets pitching coach Bob Apodaca, who has handled the Colorado Rockies’ staff since 2003, asked to be reassigned in the organization on Tuesday — before Washington unleashed its 21-hit barrage. The Rockies’ pitching has been dreadful all season.