Lately, there has been a lot of discussion that the Mariners have interest or should have interest in signing Prince Fielder. The rumors seem a little more believable when you take in account that Seattle General Manager Jack Zduriencik was responsible bringing Prince Fielder to Milwaukee in the first place. I have just one piece of commentary in response to the rumors and musings: Don't do it Jack.Yes, Prince has been a great player the last few years amassing a fairly good amount of WAR; 23.5 WAR over the last seven years to be exact. That averages out to about 3.35 WAR per year. If you throw out his first year where he only played 39 games, the average WAR jumps to 3.9 per year, which is pretty good but not superstar level.
A further examination of Prince's numbers presents a giant red flag from a risk perspective. In 2006, he only amassed 1.3 WAR followed by 5.1 WAR. In 2008, he only accumulated 1.7 WAR and followed that by a 6.4 WAR breakout season which he then followed up by dropping back down to a human 3.4 WAR year. In 2011 his contract year, Prince put up great numbers on his way to a 5.5 WAR season. So what can we infer from Prince's numbers as they are segmented? It appears that as player, he is a volatile asset. 33.3% of seasons he has played, Prince has put up a WAR that is less than 2. Additionally, after each season he eclipsed 5 WAR, Prince has produced a WAR under 4. Given the pattern demonstrated so far, it seems very likely that Prince will produce a WAR over 4 next season, especially if he changes leagues doubly so if he plays as a DH instead of a 1st baseman, as the position adjustment will adversely affect the WAR total.
Being mildly inconsistent is not the only concern that one may have. There is a premise that big bodied sluggers such as Prince tend to have their WAR decline fairly fast after their prime. To substantiate this, I offer the following examples. The first and often most cited example is that of Mo Vaughn, who went from 6.6 War in his age 30 season to just 1.9 WAR the next. Another example is probably the most accurate representation for Prince. I'm talking about one of his least favorite people, his father Cecil Fielder. Cecil was know for his mammoth power but his decline started fairly early on. In his age 27 season, Cecil put up a stellar 6.8 WAR season and then the decline started, dropping to an above average 4.3 WAR the following year. That was followed by a 3.1 WAR in his age 29 season and then Cecil fell all the way to 1.6 WAR in his age 30 season.
When one examines the data pertaining to Prince and add in the decline of large bodied sluggers to include his own father, it makes it hard to warrant a the eight year $180 Million deal he is rumored to ask. Even when you factor in the estimates that he will probably get a 6 year $120 Million deal instead, it still is enough to make a GM to reconsider. As stated before, just stay away Jack.
Note: I used fWAR and not bWAR for the post.
Per some of the comments, I thought it best to also provide a visual of what would have happened if Prince had hit the exact same this year but at Safeco. I took his spray chart from texasleaguers.com and overlaid Safeco Field.