Elvis Andrus was a top prospect for a long time before emerging as one of the better shortstops in the AL last season. His plus glove came through at ML level, the metrics were very positive for him (+14 DRS, +13 UZR), and his bat played surprisingly well, with a near league average .322 wOBA.
Andrus' prospect status was generally based around his glove at shortstop, although evaluators held out hope that he would develop into a leadoff hitter type with some development. But, generally speaking, his didn't exactly thrive with the bat in the minor leagues. Most of the hype was based around his youth relative to his peers, and the belief that he could eventually develop the patience to go along with a pretty good contact bat. His walk rates in the minor leagues were in the 7-10% range, although he did manage to cut down on his strikeouts and improve his performance as he moved up the minor league ladder.
His 2009 was pretty impressive, as at just age 20 he posted a better strikeout rate and a higher isolated power than he ever had in the minors, and even had a solid 7.4% walk rate to top it all off. Most of the projection systems, with the exception of CHONE, expected Andrus to improve somewhat in 2010 offensively, with ZiPS projecting a .332 wOBA before the season. Andrus began the season where he spent last season, at the bottom of the order, but Julio Borbon's struggles in the leadoff spot opening it up for The King.
Andrus has done nothing short of thrive in the leadoff spot, showing more patience than ever before. He's tied for 7th in the AL with 21 walks, which covers 16% of his plate appearances, and his .416 OBP is good for 7th in the AL as well. And while he's been relatively lucky with his BABIP, he's also got a very high line drive rate (25.7%) and a low infield fly rate (5.6%), and he's turned his speed into 13 steals, although he's also been caught five times. Before the 2009 season, MLB.com said of Andrus that, "[He] has made great progress offensively and is developing into a future leadoff hitter."
Apparently, the future may be now. ZiPS now projects Andrus to finish the season with an 11% walk rate and a .362 OBP for the year, good for a .344 wOBA and roughly 8.5 runs above average per 600 plate appearances. When Andrus was considered one of the best prospects in the game, much of it relied on Elvis developing the plate discipline to take advantage of his contact ability and speed. He's only 21, but he appears to already be taking the strides necessary to turn into a star. If he proves to be a legitimately above average leadoff hitter, Andrus might already be the best shortstop in the AL not named Derek Jeter.