A few days after Christmas in 2015, Aroldis Chapman was traded to the New York Yankees for four prospects to the Cincinnati Reds. As the trade ink was finalized, many started to wax poetically on how good of a bullpen the Yankees were about to have now that they added the Cuban lefty to the mix. So far in 2016, that's all been proven mostly true, but it's been the dominance of their setup men that has kept the Yankees afloat so far in 2016.

The 2016 Yankee Bullpen

To think that this bullpen became suddenly great solely due to the addition of Chapman would be a gross understatement. Andrew Miller and Dellin Betances, along with Chapman, are all putting up fine statistical marks so far in 2016:

One measure of reliever dominance is measure in their strikeout rate (K%) and their strikeout minus walk rate (K-BB%). What you'll notice immediately is the incredible strikeout rate Betances and Miller are sporting, as they're striking out more than 45% of all batters faced. Meanwhile, Miller is sporting a K-BB% mark of over 40%, while Betances is just short of that.

By comparison, Chapman, who steals many of the headlines, is under 30%.

While these statistics are great to look at in comparing the Yankees, it's better to use them to compare against other relievers around the league:

Miller and Betances lead the league not only in K% but also in K-BB% by a wide margin. Betances is six percentage points better than the third-best reliever in the league, Shawn Kelley, and five percentage points in K-BB% rate.

But strikeouts aren't everything. Below, I've shown the top-15 relievers in baseball in descending Wins Above Replacement (WAR):

You'll notice almost immediately that again, Betances and Miller are at the top of the list, with only Kenley Jansen breaking up the string of Yankee reliever dominance. Kelvin Herrera, Zach Britton and Seung Hwan Oh do trail closely behind Miller.

This Isn't a One-Year Blip

Taking a look back at the last three years, you'll notice that Betances and Miller have been largely valuable to their teams as well. The following table shows the top-15 relievers from 2014 to 2016 based, again, on WAR:

What you'll immediately notice is Betances (1st) and Miller (5th), who have performed their damage primarily as middle relievers and setup men (Andrew Miller did serve as the Yankees primary team closer in 2015, recording 36 saves). As saves are the stat many fantasy leagues are based around, closers seem to gather a lot of the attention and assumed value to their teams. Miller and Betances, however, have shown they're just as valuable or more valuable to their teams over the last three seasons. The remainder of the list is primarily dominated by closers (Chapman, Kenley Jansen, Zach Britton, Craig Kimbrel).

What's also interesting is that Betances not only leads the list, but he leads it by a very wide margin with a 7.8 WAR. He's 1.4 more WAR than Chapman, with Miller following up very closely to that next group. The 15th-best reliever on this list, Luke Gregerson, only has 3.4 WAR total.

How Good Has 2016 Been?

Breaking down qualified relievers over the last five individual seasons, a first look sorted by K-BB% places Miller and Betances current 2016 seasons in the top-10 recorded over this time span.

It's also interesting to note that Miller appears on the list a second time for his 2014 season. Only Craig Kimbrel's incredible 2012 season and their fellow bullpen mate, Chapman, sandwich their way into the top.

Again, as we mentioned above, strikeouts are certainly not the only modicum of success for a pitcher. Fielder Independent Pitching (FIP) is another useful look to determine a pitcher's value.

Miller's 2016 falls off the list, but Betances' 2016 ranks highly with the fourth-best FIP over the same five-year time span. Keep in mind that WAR is a counting stat, meaning that anyone on this list for 2016 will continue to accumulate value as the season goes along, whereas prior years obviously have a fixed value.

Overall, the non-Yankees closers are having two incredible seasons. While Andrew Miller recently inked a new deal that more properly reflects his value, Betances' 2016 salary of $507,500 is clearly not a true measure of the value to his team. By nearly any form of measurement compared to past performances, we are witnessing two absolutely dominant performances that can tend to go unnoticed by the general population of baseball viewers.