Today's home run board, built from park factors, opposing pitcher HR/9, handedness splits, weather at first pitch, and recent batted-ball form.
Each name shows the inputs behind it, so you can see why a hitter is on the board rather than taking the number on faith.
By combining the things that actually move home run rates: the park, the opposing pitcher's home runs allowed per nine innings, the handedness matchup, weather at first pitch, and the hitter's recent batted-ball form.
Dimensions and elevation dominate, but air density on the night matters more than most people expect — temperature and wind direction can move an expected home run rate materially at the same park.
In the morning for that day's slate, then revised as lineups are confirmed, since a hitter who is not in the lineup has no projection.