Christian Petersen/Getty Images
Albert Pujols is 31 years old and coming off the worst offensive season of his career. Keep in mind, he still hit .299 with 37 homers and 99 RBI.
Regardless, he is the No. 1 first baseman on the market.
Prince Fielder is next. Yes, he's four years younger and drove in 21 more runs than Pujols, but his glove isn't nearly as trustworthy.
By traditional statistics, Pujols (11 errors, .992 fielding percentage) barely edges Fielder (15 errors, .990 fielding percentage) in the fielding department. However, Pujols is superior in UZR, which essentially measures a player's range.
Since Fielder became an everyday first baseman in 2006, he has accumulated a minus-36.3 UZR. In other words, since 2006, Fielder is 36.3 runs worse than the average first baseman. His range will only decline with age.
Pujols, during that same time span, has a 53.6 UZR.
Pujols' defense has fallen from its peak in 2007 (24.7 UZR) to 2.4 in 2011, but that's still much more reliable than Fielder's minus-5.1.
Because of age, Fielder will probably be a better hitter than Pujols deeper in the future. But how much longer can he actually play first base?