There are many people complaining about the Nationals offense and in particular Bryce Harper, Ryan Zimmerman, Danny Espinosa, and Ben Revere who are all slumping.
The 9 primary batters for the season have improved at an average OPS rate of .017 per batter over 2015. If you believe Daniel Murphy and Wilson Ramos should be excluded from the chart then the batters got worse by -.o44 per batter.
Note that Bryce Harper is still 3rd in OPS on this 2016 team and 5th in batting average.
There are 61 games remaining in the 2016 regular season. There is time for additional improvement.
