What's Rosario going to bounce back to? His BA in 2016 was better than it was in 2015. His OBP in 2016 was better than it was in 2015. His K rate was up slightly this year, but not significantly. His walk rate was up slightly (again, not significantly) The area where he was 'worse'? His slugging % was down this year, compared to last year, due to an unsustainable amount of triples he had in 2015. This was predictable and was mentioned when people were talking about who was likely to be most disappointing this year. He was basically the same player he was last year, at least offensively. And, defensively, the league figured out he could throw so his assists went down cause less ran on him.