Inciarte's .367 BABIP vs LHers is over the entire 2016 season. That unsustainable number is directly fueling his success against LHers, and is why folks like to think he is suddenly playable vs LHers. His career BABIP vs LHers, including this unsustainable lucky season, is .307. When he regresses back to that number he will regress back towards his career .650 OPS vs LHers.
As a point of reference, Ichiro's career BABIP is .340, and he is the ultimate low power speedy hitter of our time.
He will be a leadoff option vs RHers in 2017, but vs LHers he either needs to be benched or at the very least moved down the lineup.
And his BABIP against RHP is below his career norm. Overall his BABIP for the year is right where it has been.