Originally Posted by MoneyInTheBank
This disclaimer is attached to those splits...
"vs Starter batting splits are for the entire game when the starter was LH or RH. These splits include any subsequent plate appearances against a reliever regardless of their throwing hand. These splits are a proxy for platoon splits for seasons we lack play-by-play data. from GL team pitching splits indicate how batters did against the team and use the batter's overall batting handedness for this split."
So the 911 PA in "LH Starter" are not just against the starter only, but for the whole game even after the starter was taken out.
That's interesting. I did not think about following the link to read that until you mentioned it. Everything makes sense again