David Robertson looks just like he did three years ago

The Yankees let David Robertson walk after the 2014 season. New York was the team that drafted Robertson, and he gave them seven productive years before skipping town to Chicago. The Yankees never seemed that engaged in re-signing their homegrown closer back in 2014, not after bringing in Andrew Miller on what in retrospect was a bargain of a four-year, $36 million contract.

Seeing a player like Robertson walk was no fun, but it was a defensible idea. The Yankees had acquired another closer in Miller, and had Dellin Betances coming off of a superb season. Keeping Robertson seemed like something of a luxury, not a necessity, especially considering the salary he would receive as he entered his 30's.

Things have changed since then. Teams are placing a premium on high-end relievers that can dominate in October, perhaps in response to the success the Royals had employing this strategy during the playoffs in 2014 and 2015. The strategy makes sense: off days in October mean teams have the ability and incentive to pitch their best relievers as much as possible. Now, having three or more great relievers no longer seems extravagant, as it's just par for the course for a team with dreams of World Series contention.

So Robertson is back, along with Tommy Khanle and Todd Frazier in the trade that sent 2016 1st round draft pick Blake Rutherford to the White Sox. The Yankees' bullpen has been in a bit of a funk of late, but recent blips aside, the trade that brought Robertson back into town has given the Yankees a bullpen armada that is simply unmatched across baseball.

Robertson has been a big part of that. What's remarkable about Robertson's performance this year is how it has mirrored his initial stint in pinstripes. Even at age-32, three seasons removed from his last season in New York and what would technically be referred to as his prime, Robertson looks almost exactly as he did when he first was with the Yankees.

Across the board, Robertson's numbers from 2017 are strikingly similar to those from 2011 to 2014 (the years that reflect his peak performance during his initial stretch as a Yankee). Here's a sampling:

His peripherals in 2017 almost exactly match those figures from his first time in New York. His run prevention numbers are still spectacular. For all intents and purposes, Robertson is just as good now as he was when he left.

Not only that, Robertson looks similar both in terms of results and actual on-field performance. He's generated 47% groundballs this year, and he generated 47% groundballs across 2011 to 2014. Per FanGraphs, he's allowed a 26% hard contact rate, better than league average, in 2017, the same as the hard contact rate he yielded between 2011 and 2014. He's thrown pitches in the strike zone (44%) at the same rate this year as he did in his final four years as a Yankee.

Perhaps most encouragingly, Robertson has been able to mostly hold his velocity since 2014. According to Brooks Baseball, Robertson averaged 92.0 mph on his signature cut-fastball in September 2014, his final month before signing in Chicago. His average velocity in 2017? 92 mph (though it should be noted his average cutter velocity across all of 2014 was a few tenths of a mph higher than just September).

Robertson looked like he might've begun to drop off in 2016, when his ERA inflated to 3.47 and his strikeout rate dropped to about 10 per nine innings. Instead, he's returned to the Yankees this year playing as well as he did when he left. He's allowing just as few runs, whiffing just as many batters, and throwing just about as hard as he did when we last saw him in 2014.

This is highly encouraging considering the Yankees made the move that brought Robertson back primarily because it strengthened them now and in the future. Both Robertson and Kahnle are under team control in 2018, Robertson at a price of $13 million. That may seem a little steep for a 33-year-old, but that Robertson has so well replicated his initial play with the Yankees this year bodes well for his chances of being worth every dime the Yankees pay him going forward.

That the Yankees could bring Robertson back after letting him go almost seemed like a slice of fan service worthy of recent seasons of Game of Thrones. Yet he's actually back, as good as ever, as if he never left. The Yankees' bullpen, as a result, should be among the strongest overall units in the game over the next couple seasons. For a team that now has designs on deep postseason runs, the addition of vintage-Robertson is excellent news.