The Z Files: 2020 Park Factor Notes

As if things weren't already challenging. I'm still trying to wrap my head around how to deal with the "What ball will be used?" issue, and now we must adjust a pair of extreme pitching parks along with guessing how a new venue will play? Good times.

Yes friends, it's time for my annual look at park factors, a necessary evil. Before we delve into what's new for 2020, here's an overview of the topic.

Park factors quantify how a venue plays, independent of the quality of the home team's hitting or pitching. The formulas are designed to minimize bias, but it always doesn't eliminate it. Still, it's better to incorporate park factors in analysis than ignore them.

Park indices are expressed so a neutral park is 100. A factor of 110 means the venue increases the stat in question by 10 percent. A factor of 85 indicates it decreases the stat by 15 percent.

By means of example, say a batter is projected to hit 20 homers in a venue with a HR index of 100. If he played in a ballpark with a 120 index, his new projection would be 22, since the 10 projected homers at home jumps to 12. if he played in a place with a 90 index, his new expectation is 19, since he'd lose 10 percent of his 10 homers at home. While it goes beyond the scope of this piece, factors do not affect each player linearly, but it's best to apply