WHAT HAPPENS WHEN YOUR GROUNDBALL RATE GOES UP BY 10%
> Allen Craig is not himself this year. The apparent reason is that he can’t get the ball off the ground, causing his power to plummet. Below are all the instances I’ve found of players whose groundball rates increased by 10% or more from one 350+ plate appearance season to another since 2002, when Fangraphs first began collecting the data.
The last column compares the player’s career ISO (slugging minus batting average) prior to his increased groundball season to the three seasons after. I chose three because Craig has three guaranteed years left on his contract.
350 plate appearances (Craig’s current approximate season total) is usually enough to establish what a guy’s groundball rate is. But to strip away any possible flukes, here are changes of 10% or more across two 450+ plate appearance seasons.