Andrew Miller vs. David Robertson

The Yankees signed  left-handed reliever Andrew Miller on December 5th to a 4 year/$36 million contract. Four days later, the White Sox signed David Robertson to a reported 4 year/$46 million contract. Both players were in the Yankees’ offseason plans. Only one of them will help anchor their bullpen in 2015 and beyond. Did they make the correct choice?

Projected Performance and Track Record:

First, the 2014 numbers for each pitcher. Miller: 62.1 IP, 51 ERA-, 39 FIP-, 42 xFIP-, 42.6 K%, 7.0 BB%. Robertson: 64.1 IP, 78 ERA-, 69 FIP-, 57 xFIP-, 37.1 K%, 8.9 BB%. Miller was better with the higher strikeout rate, lower walk rate, and fewer runs allowed. Both guys were elite relievers, however, in 2014.

Now, the career numbers with 2014 baked in. Miller: 167.2 IP (as reliever), 32.8 K%, 12.1 BB%, 3.38 ERA, 3.02 FIP, 2.97 xFIP. Robertson: 393.1 IP, 32.0 K%, 10.2 BB%, 2.81 ERA, 2.74 FIP, 2.82 xFIP. Robertson has over twice as many innings thrown as a reliever. The strikeout rate is similar while Robertson has walked slightly fewer batters and has kept runs off the board at a better rate. Robertson has a longer (and better) track record as a reliever than Miller.

And finally the Steamer projections for 2015. Miller: 34.0 K%, 8.4 BB%, 2.40 ERA, 1.2 WAR. Robertson: 30.0 K%, 7.8 BB%, 2.82 ERA, 1.0 WAR. A 0.2 WAR difference is splitting hairs. WAR isn’t precise enough to say that’s a meaningful difference. These pitchers are projected as equals for next season.

Contract and Age:

Both players received 4 year deals and shelling out 4 year contracts to relievers, no matter how effective, is generally a poor idea. The attrition rate on these guys is just too high. Relievers burn hot and fast. However, there is so much money in the game and few places to spend (draft and international spending now capped) that slightly overspending on an elite reliever won’t hurt too much. Robertson received $11.5 million in AAV while Miller attained $9 million for a total gap of $10 million. That sounds like a lot but the current $/WAR is around $7 million. This is what teams are paying for projected performance right now. That figure could easily be around $10 million in 4 years with the increasing inflation in MLB. Therefore, this gap in dollars indicates around a 1 WAR difference in projected value across the life of the deal. The $10 million difference just isn’t a lot in the current market environment. Both are 29 years old. Robertson is just 1.5 months older, a negligible difference.

Miscellaneous:

The fact that Robertson has recorded some saves on his career ledger and Miller has not is immaterial. Miller can be great in the 9th just as he was great in the 7th and 8th. The right-handed versus left-handed factor is also a non-issue. Both players can generate outs against players who hit from either side of the plate. Miller’s slider is still very effective against righties and Robertson’s 12-6 curve engenders no platoon split. A factor that might be relevant as a slight tiebreaker is the fact that Robertson has played in New York before. That could be very relevant in that he doesn’t have to adjust to a new pitching coach, new teammates, new city, etc. These are human beings, not Strat cards. Miller might face a slight learning curve in New York. Letting Robertson sign with another team garners a draft pick for the Yankees. They don’t have to surrender a draft pick to sign Miller.

Conclusion:

The projections are basically the same and, in a vacuum, choosing either pitcher for next year is a cromulent idea. Taking context into account, paying a slight premium for Robertson’s New York experience and much bigger track record might be the right move. However, receiving the compensatory draft pick by letting Robertson walk is valuable. In the end, the Yankees valued the draft pick compensation from not resigning Robertson and the slight cost savings over the track record of Robertson and his familiarity with New York.