"Josh Howard's tenure with the Mavericks, which began with quality production but eroded into inconsistency and controversy, is coming to an end.The Mavericks have reached a tentative agreement to send Howard, Drew Gooden and two other players to Washington for swingman Caron Butler, center Brendan Haywood and guard DeShawn Stevenson, numerous NBA sources said Friday.Though the deal still needs league approval, both sides have agreed on the moving parts in a trade that will cost the Mavericks more money but brings them more talent, at least in the short run.Butler is under contract through next season, at a cost of more than $10.5 million. He figures to slide into the role that Howard was playing, although he also could start if Jason Terry is moved back to the sixth-man role.Haywood, who is averaging 9.8 points and 10.3 rebounds, is in the final season of his contract, which pays him $6 million."