It was bound to happen at some point. Once every so often, some GM signs a player to a contract that has people scratching their heads and saying "absolutely bat**** crazy". This year's "Are you kidding me?" award goes to Nationals GM Mike Rizzo, who signed outfielder Jayson Werth to a 7-year, $126 million contract.
Four years ago, Cubs GM Jim Hendry received a lot of flak for signing outfielder Alfonso Soriano to an 8-year, $136 million contract, which at least one blogger called "the worst contract in baseball history." Cubs fans are just beginning to understand what that blogger meant, as Soriano's contract is one of the reasons that Hendry options are limited this offseason.
At the risk of making Jim Hendry look good, let's compare the two contracts and see which one could end up being the worst contract:
Werth had a strong year in 2010, posting the highest OPS mark (.921) of his career. However, Soriano was coming off his career year, hitting .277/.351/.560 and becoming just the 4th memeber of the 40/40 club along with Alex Rodriguez, Barry Bonds and Jose Canseco (a Who's Who of the Steroid Era). That and the fact that he did it in a notorious pitcher's park in Washington was enough to drive up his asking price.
However, if you look at their career stats at the time of their signings, the picture gets a little muddier. Werth had the higher career OPS (.848 to .836) and a higher cumulative OPS+ (OPS adjusted for park effects) of 719 to Soriano's 689. However, Soriano had a higher cumulative oWAR (offensive wins against replacement) of 22.6 to Werth's 15.6. Werth is hurt by the fact that he didn't become a full-time player until 2008 (when he turned 29) and that he missed his entire age 27 year due to injury. Soriano is hurt by his inability to take a walk (for a leadoff hitter, no less).
Finally, Soriano averaged more homeruns and stolen bases than Werth, as well as rbi's and runs. However, this again is skewed by the fact that Werth did not become a full-time starter until later in his career.
Overall, I would give a slight edge here to Soriano.
This one is a little more difficult to evaluate, as Soriano switched positions in the year before he signed his contract. In his first 5 full seasons, Soriano played second base and played it badly. His cumulative dWAR during that time was -7.8. However, in his one year with Washington, Soriano was moved to left field and posted a respectable 1.6 dWAR. As the Cubs were signing him as a left fielder, they could overlook his poor play at second and see that he was at least an above average outfielder.
As for Werth, he posted decent dWAR's ranging from 0.3 to 1.3 in his first 4 seasons, before being exposed in 2009 (-0.8) and 2010 (0.0). Some of this could be attributed to his playing out of position in center field for 33 games in 2009 and 2010, however it doesn't explain the total drop off.
Finally, if you look at their range factors, Soriano's one year RF/9 in left field of 2.28 was better than Werth's career RF/9 in right field of 2.18, and if you look at their final year before they signed, the difference was even greater (2.28 to 1.98).
Overall, evaluating them both as just outfielders, the edge would have to go to Soriano.
When he signed with the Cubs, Soriano was moving from a pitcher's park (0.86 HR park factor) to a hitter's park (1.21 HR park factor), whereas Werth is moving from a hitter's park (1.13 HR park factor) to a pitcher's park (1.00 HR park factor) per ESPN's park factor database.
Also, Soriano signed after his age 30 year for 8 years, wheras Werth is signing after his age 31 year for 7 years, thus both contracts run through their age 38 years. Werth gets $1 million more per year, but we can chalk that up to inflation.
Based on the above, one can make the case that Hendry may be off the hook as having signed the "worst contract in baseball history", as Soriano seems to have an edge in each category. However, as they say in the world of investing, past performance is no guarantee of future results. As seen with Soriano, knee injuries have taken away his ability to steal bases and hurt his defense, thereby decreasing his value significantly over the last few years.
It remains to be seen how Werth will perform over the life of his contract, but as is typical with the long-term contracts signed after the age of 30, one would expect that, by year 4 or 5, the Nats will be regretting this contract (if they aren't already).