Soriano? Good. But 8 Years?

As you know, the Chicago Cubs just signed Alfonso Soriano to the richest contract in club history, $136 Million over 8 years. For those scoring at home, that comes to $17 Million a year. I think its a good move over the first half or so of the contract, but how good will it be for the second half of those 8 years, when Soriano is on the wrong side of 35? Let's try and find out.

They have a cool little feature (well, lots of cool things really) over at Baseball Reference, but we're going to work with the Similarity Scores today. Basically, it looks at various stats for a player and matches him with other players who put up similar numbers. The best two matches for Soriano look to be Matt Williams and Jeff Kent. The next two would probably be Danny Tartabull (he of Seinfeld fame) and Raul Mondesi. In the last group, I put Ken Boyer alone, mainly because he played in a different era. Anyway, lets look at the results:



As you can see, Kent and Boyer had better seasons than Soriano, and Williams and Tartabull were very close. Now Lets see what happened to these players rate stats in the years after they turned 30:




Jeff Kent was easily the most productive hitter after he turned 30, while Raul Mondesi struggled the most. Tartabull's career was cut short by injuries, and Boyer and Williams both struggled towards the end of their careers. Some graphs might better illustrate the effects:






As you can see, there is a general downward trend in production as players age, which is obviously to be expected. We can probably go ahead and throw out Mondesi's numbers, as he is far below everybody else and played for a shorter time. Tartabull also played for too short of a time. It is reasonable to expect production somewhere around what Matt Williams and Jeff Kent did for the first few years, but after that it's really anyone's guess. I fully expect Soriano to have between at least 6-7 RC/27 the next few years, but probably drop off a little after that, to about where Matt Williams was. Although he could be like Kent, who did not suffer this drop-off. If Soriano becomes the kind of player Kent was, the Cubs will be very happy. Even though that's probably not worth $17 Million, the market is what it is I suppose.