Tom Tango and Phil Birnbaum discuss crediting pitchers and fielder properly on outs and hits on balls in play.
When I worked on the Probabilistic Model of Range (PMR), I liked to list PMR behind pitchers. The display would show the probability of the pitcher’s balls in play being turned into outs, and the actual percentage of outs recorded by the fielders. I ran it as a way of seeing pitchers who were helped or hurt by their defense, but it also showed which pitchers were doing a good job of inducing easy or tough to field balls in play.
It strikes me that this could be used as a way to properly weight credit to the pitcher and the fielder. Pitchers who induce easier to field batted balls simply get more credit that those who make life tough for the fielders. I’m sure some clever person could work this out.
I didnt open the link but I think if MLB ever makes the data from statcast available in a usable format I think using the batted ball velocity will make the task easier and more practical.
I don’t think a pitcher can control the direction or vertical angle of a batted ball with any precision, although general GB/FB tendencies and pull/not pull may be somewhat within their control (some pitchers anyways).
However, its a pitchers stuff and command within the strike zone that controls the quality of contact IMO, and the batted ball velocity has the biggest effect on whether a ball goes for a hit than any other variable.
Of course, as an equity holder in online gambling for baseball I am not sure MLB wants to give the bettors more useful information in which to make better bets. Less profit for the house means less returns on their investment.