He is notable not for his below-average defense at first base, but for being one of the best pure hitters in baseball's history. He has been compared to being as close to a right-handed version of Ted Williams there is. A slugger who hits 35-40 home runs a year as a matter of course, hits .330 or better most years, and most importantly, takes well over 100 walks a season, Frank Thomas has proven himself to be one of the top five right-handed hitters ever, and the second best hitter since 1990, only behind Barry Bonds. Frank Thomas's on base percentage is in the top-ten career, of any ballplayer in history.
Unfortunately, Frank Thomas has been much maligned by the media, especially in Chicago. Much of this came about after a disastrous 2002 season, in which he performed so poorly that the White Sox invoked a "diminished skills" clause in his contract. He resurrected his career in 2003; although he hit a subpar .267, he was tied for second in the American League in home runs (42) and was in the league's top ten in walks, extra-base hits, slugging percentage, and OPS.