If you ever get upset about a managerial decision during the upcoming season, just scroll back to this post from Steve Treder of the Hardball Times. Clarke's .509 OPS makes Melky look like a slugger, and that takes some doing.
GS PA R XBH RBI BB IBB SO HBP SH ROE GDP SB CS BA OBP SLG OPS
133 586 51 9 23 20 0 45 0 3 7 8 18 7 .229 .256 .253 .509
His name has since become an instant punchline, a shorthand summary of the Yankees' shortcomings between their great periods of the early '60s and mid-'70s, but in truth Horace Clarke wasn't all that bad a ballplayer. He was your basic light-hitting second baseman with good speed and a decent glove; lots of teams over the years have used guys like this in the middle infield, and plenty have been worse than Clarke.
The reason Clarke became so prominent (aside from playing in The Big Apple) was that his manager, Ralph Houk, insisted not only on playing him every day through thick and thin, but in batting him in the leadoff spot, no matter what.
Clarke in 1968 had the misfortune of timing his worst year at the plate, relative to league norms, with the league's lightest-hitting norm in about 60 years, and the result was a raw stat line that's downright scary. He produced nine, count 'em, nine extra-base hits that year, and scored 51 times from the leadoff spot in nearly 600 plate appearances. Wow.