In some ways, not much has changed for Andy Murray and Novak Djokovic since the 2016 Mutua Madrid Open. A year later, both men still sit atop the Emirates ATP Rankings, and this year, just like last, the Scot and the Serbian are among the favourites to win the season's second ATP World Tour Masters 1000 tournament on clay. But in other ways, much is different for the World No. 1 and No. 2, as both players head to this week's Mutua Madrid Open seeking similar reboots to their 2017 campaigns if they plan to keep their comfortable advantages atop the Emirates ATP Rankings. Djokovic, the 2016 Madrid champion, will be defending 1,000 Emirates ATP Rankings points, and Murray, last...