KABUL - M Nabi has stepped down as captain of the Afghanistan national side, after a little more than two years in the job, citing the team's recent performances and his own lack of form. Nabi tweeted news of his resignation and shared the letter he had sent to the Afghanistan Cricket Board on the social media website. "I have served Afghanistan's national cricket team as a captain for more than two years," Nabi said. "I tried my very best to bring victories to our team and nation.”