So...is Brad Ziegler good again?

When the Marlins first acquired Brad Ziegler in December 2016, he was fresh off an impressive season with Boston and Arizona, where he converted 22 of 28 save opportunities with a 2.25 ERA. The Marlins wanted to fortify their bullpen going into 2017, with AJ Ramos, David Phelps and Kyle Barraclough already in place. In Ziegler, they were getting a proven reliever—with a 2.44 career ERA and 85 saves—to help get the ball to Ramos for the save.

But the veteran struggled mightily as a setup guy. Through June 20 of that first Marlins season, he posted an abysmal 6.52 ERA.

Ramos was traded to the Mets in late July, creating an opportunity for Ziegler to claim the closer role. The experiment paid dividends—in 19 appearances, he got 10 saves in 13 opportunities with a 2.00 ERA.

Steve Mitchell-USA TODAY Sports

Fast-forward to this season...oh, how things have changed.

In 24 appearances as the closer (including non-save opportunities), Ziegler went 0-5 for a 7.83 ERA. Marlin fans were calling for a change early on, and after blowing a 2-1 lead against San Diego on May 30, they got their wish.

Of course, this wasn’t all on Ziegler. His defense hasn’t always been solid behind him, and has partially been responsible for an extra few runs crossing the plate. Through May 30, opponents had a .366 BABIP, which was on pace to be a career worst. Even now (entering Friday), this poor luck is reflected in his FIP (4.72) being almost a full run below his ERA (5.56).

Since the demotion, Ziegler has returned to being the pitcher the Marlins had hoped he would be. In eight appearances (11.0 IP) as a middle reliever, he has allowed only one earned run and collected four holds.

What has been the difference?

For one thing, Ziegler is utilizing mainly his sinker and slider to get plenty of ground balls. At 69.4 percent, he’s raised his ground ball rate by five points from last year. This is also his highest ground ball rate since 2015 (72.8 percent).

One other big reason for this resurgence might be the usage of that slider. In April and May, he seldom used it, only throwing it 11 percent of the time. And when he was using it, he had trouble controlling it.

As you can see below, his slider wasn’t in spots to induce ground balls and soft contact. Most ended up in the middle of the zone.

Fangraphs

The next chart shows where he’s placed the slider since June 1. He’s almost completely abandoned the upper half of the zone. This month, 58 percent of his sliders have been at the bottom of the zone/just below it. Before June 1, that number was just 39 percent.

Fangraphs

Want to see this improved pitch placement in action? Look back to June 8 against the Padres. With only one out and the bases loaded in the top of the 6th, Ziegler induced a double play to hold the lead for the Marlins.

Because of his affinity for inducing ground balls, Ziegler has become the go-to reliever for getting the Fish out of jams. Since June 1, he has inherited 12 runners and only allowed three of those to score.

Is this the new Brad Ziegler? Or just a hot streak? Only time can tell. But for now, the Marlins bullpen—already featuring dominant arms like Barraclough and Drew Steckenrider—looks even more intimidating.