The team leaders in home runs from 2004 to 2013 experienced a similar trend. Of teams that led the league in home runs at the break, only the 2009 New York Yankees and 2010 Toronto Blue Jays hit home runs more frequently in the second half than they had in the first half.

Leaders in the other years saw their numbers taper — as extraordinary production often will.

Nevertheless, concerns about the derby's consequences persist, so MLB adjusted this year's format.

Cespedes will return to defend his title in a competition designed to reduce the wear and tear of participating.

Players will receive seven outs each round instead of 10, and the top player from each league in the first round receives a bye to the third (semifinal) round, increasing the amount of rest for the competitors who took the most swings.

But the quantity of swings isn't the only problem.

"I understand they're trying to manage some of that this year, but these guys take so many full, gorilla swings that it would have to affect your swing at some point if you're in that long enough," Scioscia said.

Players typically don't take such monster cuts during a regular-season game, so swinging for the fences in the derby, some people argue, can spur the development of bad habits or cause injury.

Mattingly doesn't buy it, saying a home run derby of sorts takes place before most games, during batting practice.

"You ever watch these guys take BP?" Mattingly asked. "I mean, they're launching all the time."