After graduating a Bachelor of Arts, Tarr was articled to the solicitors firm of Owston, Dickinson, Simpson, and Bigg in Leicester, and also joined the Leicester Tigers, then as now considered one of the strongest clubs in the country. He scored 72 points in 94 appearances. In 1913, having been dropped by England four years earlier, he was surprised to be called up again to play Scotland on 15 March at Twickenham. Tarr was not at his best and it was to be his last international appearance. England, meanwhile, only managed a 3–0 victory, but it was enough to regain the Calcutta Cup and earn its first Grand Slam.
