This is an except of a post originating from Zone Coverage. Read it in full at this link.

You could be forgiven if the Minnesota Twins recalling Tyler Duffey on the last homestand didn’t register on your radar.

A lot of things are going on with this team right now — most notably, winning and hitting homers — and the return of a reliever who posted a 7.20 ERA when fans saw him last probably doesn’t many of them too excited.

But if you think it’s the same Duffey you’ve seen before, you’re sorely mistaken.

Duffey’s early results have been fairly positive — it has only been three appearances spanning four innings — as the 28-year-old righty has fanned five of the 16 batters he’s faced while allowing just one earned run.

A furtive glance at his HR/9 would indicate he hasn’t graduated from last season’s bombing, but that’s just one homer allowed in a small sample size. It doesn’t indicate much, and if the things Duffey has been working on continue to stick, that number will come down quickly.

Duffey is the newest convert to the concept of tunneling.

What is tunneling?

It’s really a simple concept that has picked up steam in recent years with the increased usage of GIFs on social media platforms like Twitter. Tunneling is the idea that the baseball travels down the same path regardless of what pitch it is, only deviating from that plane at a point where a hitter is either unable to differentiate what it is, or unable to react to it.

Basically, for a pitcher like Duffey it’s like throwing his curveball and fastball on the same plane, with the high fastball mixing beautifully with the curve down that is his bread and butter.