David Robertson and the Dangers of Reliever Volatility
Right-handed reliever David Robertson is earning $12 million per year on a rebuilding Chicago White Sox team that has little need for a high-priced closer. The Washington Nationals, meanwhile, might need a closer if they aren’t comfortable with internal options who, whatever their qualifications, lack proven closer experience. As a result, it isn’t surprising to find that the two teams have been discussing a trade. Robertson is owed $25 million over the next two years, a relatively reasonable fee given the cost of closers on the free-agent market. If the White Sox are looking to dump salary, Robertson might make sense for multiple teams, but if the Sox want prospects back, both Chicago and Robertson’s suitors might be better off waiting until July, even if the price for relievers is higher at that time.
From 2011 to -15, Robertson was one of the very best relievers in baseball. During that time, he averaged nearly two wins above replacement per season. The only relievers with a higher total WAR during that time frame were Aroldis Chapman, Greg Holland, Kenley Jansen, and Craig Kimbrel. That 2015 campaign, Robertson’s first with the White Sox, was also arguably the best of his career. He struck out 34% of batters while walking just 5%. A very low 66% left-on-base percentage gave him just a 3.41 ERA (compared to his 2.52 FIP), but the results were fine nonetheless. Entering the 2016 season, Robertson was again set to be one of the very best relievers in the game, earning a 1.9-WAR projection on our Depth Charts projection. The season didn’t go as well as expected.
Robertson put together a solid season, recording a good 3.58 FIP (82 FIP-) and a similar 3.47 ERA (82 ERA-). The result: a 1.0-WAR season, making him one of just a dozen full-time closers to hit the one-win mark last year. The results were good, but they represented a decline from his elite numbers the five years prior to 2016. His strikeout rate dropped from 34% to 28%; his walk rate more than doubled, up to 12%, after having remained below 9% since the 2011 season. Last season might be an outlier. It’s possible that Robertson return to form this year. It could be a new normal for Robertson going forward, though — or, worse, it could represent a decline that could continue into this season. The problem is that nobody really knows.