Plenty of weak-hitting players from baseball's past and present have gotten by on good gloves alone. Most big league benches boast a part-timer or two whose sole strength is an ability to play capable defense at premium positions. But despite Brendan Ryan's best efforts, relatively few players become stars unless they can combine good gloves with big bats.
Fortunately, not every good-fielding, no-hitting player is destined to stay that way. Legendary glove man Ozzie Smith was a good player who turned into a great one when he learned how to hit in his late 20s. Defensive players of Smith's caliber are rare, but some of today's finest fielders could follow a similar trajectory.
The following five defense-first players entered 2012 with reputations as easy outs but have become much better at the plate. The question is, are these gains for real, or are they just single-season anomalies?