While looking at the top fantasy performers so far at every position, second base is the most surprising.With Ketel Marte (hamstring) battling injuries, Jose Altuve and Marcus Semien starting to show their age, and up-and-comers like Matt McLain and Jordan Westburg not breaking out as expected, the top of the position rankings has been ripe for the picking for potential challengers.Let's look at a few guys who have taken advantage of this opportunity. They are some of the top second basemen for ...