High grass as in a batter is clever enough to bunt into it and take advantage. Smart, not lucky.
High wind as in a batter being lucky that his fly ball was blown over a wall for a home run.
How do we know about either?
Statcast and the Future of WAR
by Dave Cameron - March 6, 2017 fangraphs.com
... Sloan Sports Analytics Conference ... latest update to Statcast ... two new public metrics for 2017, Catch Probability and Hit Probability...
one of the first steps in moving from collecting interesting single data points into providing more valuable calculations based on the combination of factors the system is measuring...
catch probability ... is outfield only right now, as infield calculations are more complicated ... closer than ever to being able to build metrics that directly measure the quality of contact a pitcher allowed, and adjust both the pitcher and the fielder’s contributions to the play made (or not made) based on that important variable.
So, yeah, Statcast is going to improve WAR calculations in a significant way, and should allow us to move past the FIP/ERA divide in the not-too-distant future... how granular should WAR get? ...
WAR, generally, is a descriptive metric; it is trying to measure the value a player produced in a given season, not tell you what his value will be next season...
... Andre Ethier home run from last year’s NLCS.
According to the new Statcast Hit Probability calculation, a ball hit at that exit velocity and launch angle is an out 95% of the time. Because of a favorable wind and the fact that the ball was hit in one of the few stadiums where a 353-foot fly ball to left center would clear the fence, Ethier actually got his first home run off a left-hander in three years...
He didn’t really have control over the wind carrying his weak fly ball into the seats.
Like most articles in fangraphs, this one is well written and at least twice as long as it should be. Read the rest for yourself but the point is that Andre Ethier was lucky because the wind was blowing out.
How do we know that Ethier didn't know that and was smart enough to use that wind to his advantage?
There still seems to be an implicit bias in favor of scientific styles of baseball versus power styles. Small smart guys versus big dumb guys. Smart analysts versus dumb analysts.
And more generally, if a batter hits the ball at a fielder, the fielder will catch it. It's just a matter of where the fielder is playing, not any special fielding talent.
If the batter hits the ball hard and right at a fielder, we tend to think that the batter was unlucky. Maybe. But the objective is to hit them where the fielders ain't, including into the seats with high wind blowing out. Or into high grass.