When baseball executives and players try to explain why run production has plummeted in recent seasons, they offer a range of theories, from MLB played without amphetamines and steroids to the impact of defensive shifts. But there is one common thread: The bullpens have become stacked with guys who throw really, really hard, with many teams presenting a parade of relievers firing mid-90s fastballs after the fifth inning.

In the second part of our top 10 team element rankings, let's break down the bullpens.

1. Kansas City Royals

If not for Giants starter Madison Bumgarner's superhuman feats, the Royals would’ve won the World Series and their relief corps would’ve taken a place in history alongside the Reds’ Nasty Boys for being the core of a championship. But in some ways, the Royals’ trio of Greg Holland, Wade Davis and Kelvin Herrera accomplished stuff we really hadn’t seen before. That group faced 960 hitters last season, struck out 309 and allowed a total of three homers. Davis ranked No. 1 among all relievers with 60 or more innings in limiting opponents’ OPS last season (.408); Holland was sixth, and Herrera was 21st. Even if the Royals had a lot of mediocrity in other spots in their pen, the work of that trio would have Kansas City at No. 1 in these rankings.

But the Royals will also have Jason Frasor and Tim Collins, and Luke Hochevar is expected back after missing all of last season because of elbow reconstruction.