TEHRAN, July 23 - On July 25, Pakistanis will head to the polls for the country's second-ever democratic transition of power. There are dozens of parties in the fray, with two main contenders: ex-cricket hero Imran Khan's Pakistan Tehreek-i-Insaf party and the Pakistan Muslim League-Nawaz, which vows to win a second term despite the jailing of founder, ex-Prime Minister Nawaz Sharif, on a corruption conviction.