Home runs are flying out Major League Baseball parks at a record rate. But unlike the late 1990s — when it turns out the rash of dingers was related to players enjoying performance-enhancing drugs of various sorts — this one has the general public baffled. Are baseballs themselves juiced? Are the bats making a difference?

Neil Greenberg, sportswriter for The Washington Post, says it’s much more scientific than that — having to do more with how hitters swing.

He’s with me to talk more about that. And the timing is good, thanks to Major League Baseball holding its Home Run Derby tonight, the evening before the All-Star Game.