Despite returning Trevor Rosenthal and Carlos Martinez to the back end of the bullpen in 2015 to go along with emerging Marco Gonzales, trusted Seth Maness and a few other arms like Sam Freeman and the potential of Sam Tuivailala, the Cardinals appear to be targeting the free agent market for bullpen help. One of the potential targets includes Andrew Miller, who is likely to be expensive and need a multi-year deal. The Cardinals do have money to spend, but generally, spending big money for multiple years on relievers is a poor way to spend money.
When it comes to getting the most bang for your buck, spending on relief pitching is probably the worst way to go. While it can be argued that WAR is a poor way to value relievers because it does not give enough credit for pitching in high leverage situations, fWAR does take into account leverage and gives relievers extra credit for pitching in late, close games. Despite the extra credit for pressure-filled situations, relievers are generally the most expensive free agent acquisition when it comes to valuing a win.
Even if WAR is a poor way to value relievers against players at other positions, we can still use fWAR and ERA to compare relievers among each other. Last season, there were 46 relief pitchers who finished in the top 30 in either fWAR or ERA among relievers in 2014. Of those 46 players, just four were signed to multi-year free agent deals. Of those four, three players were in the first year of their deal with significant money still remaining on the contract.
Joaquin Benoit ($9.5 million remaining), Fernando Rodney ($7 million) and Joe Smith ($10.4 million remaining over two years) all pitched well this season, but still have significant sums of money owed to them next year. The one player in the middle of a free agent deal who performed well in 2014 was Jonathan Papelbon and he is in the middle of a four-year $50 million dollar deal that Philadelphia has been unable to trade despite not contending over the past few years.
Just because the majority of good relievers are either home-grown or signed to one-season deals does not show that the deals teams do make do not work out. Last offseason, fifteen players signed multi-year deals (contracts from MLB Trade Rumors tools, statistics from Fangraphs Custom Leaderboards). Here is how they performed in 2014 (averages are of the whole groups accumulated statistics).
|Matt Thornton||- - -||2/7||36||7||2||1.75||2.66||0.7|
|Edward Mujica||Red Sox||2/9.5||60||6.45||2.1||3.9||3.7||0.4|
As a group, the players declined from 2013 to 2014 after signing the contracts. Relief pitching is very volatile year to year. There are larger contracts at the higher end and lower end of this group. Signing a big contract does not guarantee performance.
Looking at the overall performance may leave you thinking the group did fine as a whole, and that is true. League average for reliever K/9 is 8.5, for BB/9 it is 3.3, ERA is 3.58 and FIP is 3.60. The reliever group actually beat relievers as a whole in ERA and FIP, but the group is overall an average group and sinking money for an average reliever is not the best investment. When you consider that only three out of fifteen relievers had what most would consider good years and five relievers were at or below replacement level, the hit rate is not high. To make matters worse, all of these relievers were in the first year of their contracts. They are still owed money in 2015 with three relievers owed money into 2016.
There were twelve relievers signed to multi-year deals heading into 2013. Of those, Sean Burnett and Tom Gorzellany pitched less than 25 innings combined in 2014. Jason Grilli and Jonathan Broxton have already been traded. The Cardinals are looking to ditch Randy Choate. Brandon League and Craig Breslow have been disasters in 2014 for the Dodgers and Red Sox. Jeremy Affeldt and Santiago Casilla have pitched decently well, and among the successes like Joel Peralta, Carlos Villanueva and Rafael Soriano, none of the players exceeded Soriano's 0.8 fWAR in 2014.
Looking at Andrew Miller's incredible 2014 makes it look like handing out a long-term deal is worth further solidifying the back-end of the bullpen, but those deals tend to backfire more often than they succeed. Reliever performance tends to fluctuate on a yearly basis. There is a reason the Cardinals chose not pursue Mujica last offseason and a reason the Cardinals are unlikely to re-sign Pat Neshek after a great season in 2014. Those performances cannot be counted on for the future. The Cardinals are better off going the minor league free agent route like they did in 2014 with Pat Neshek and David Aardsma. They are not likely to find the next Pat Neshek, but spending big money on a reliever is not likely to yield great results and the money is better off used to obtain more cost-effective players.