Already, six first-time NBA coaches have been hired this summer — and the Boston Celtics and Philadelphia 76ers still have vacancies. Denver nabbed one of them, perhaps the most heralded of the bunch in Phil Jackson protege Brian Shaw, introduced Tuesday as the 20th Nuggets coach in history. According to an NBA source, Shaw signed a three-year deal with an option for a fourth year, and the former Indiana Pacers assistant coach will have an annual salary in the $2 million range. George Karl, who Shaw replaced, made around $4.5 million. Denver still has to pay Karl, who was let go earlier this month.