Well, Ottavino was a very good reliever from 13-15. He blows out his elbow in 15, returns in 16 and was pretty good. 2017 saw a rise in BABIP above where he had been as a reliever by a lot and an uncharacteristic jump in walks and homers. Last year, the BABIP went down to his reliever standard, the walks came down (albeit not to where he usually sat in the 3.5 range) but the K’s rose and HRs fell off entirely. He’s a good reliever who’s experience Tommy John and one bad season over the last 4 years. He’s also added a cutter which adds to his effectiveness, a la Eovaldi
Eovaldi has had it done twice. That’s a rare club. Also, Eovaldi has been unable to reach 30+ starts outside of a single season. He’s frequently injured and has now had a twice reconstructed elbow.
Right now - being pragmatic - the Yankees have closed the gap on paper with Boston. Paxton is a significant boost to the team's biggest weakness, and Ottavino helps the bullpen. The Red Sox have not enhanced the 2018 roster, and is probably losing Kelly and Kimbrel. (how much that hurts is hard to tell) We're lucky that Hal is content to pocket the Bombers' revenue instead of actually attacking this tremendous free agent class with more vigor. But that dig applies to all 30 teams to some degree or another.
Boston is counting on more internal improvement - that the October Devers shows a guy who has turned a corner for instance.
We beat New York by eight games. Now , they certainly seem to have improved , even without Machado. Have they improved enough to make up the difference ? That is the burning question. To beat a dead horse one more time , I think we are playing a dangerous game by virtually ignoring the bullpen.