In baseball, corner outfielders are outfielder

Outfielder

Outfielder is a generic term applied to each of the people playing in the three defensive positions in baseball farthest from the batter. These defenders are the left fielder, the center fielder, and the right fielder...

s who play the corner positions of right field and left field. Corner outfielders often have less speed than center fielder

Center fielder

A center fielder, abbreviated CF, is the outfielder in baseball who plays defense in center field – the baseball fielding position between left field and right field...

s, but make up for this deficiency with their bats. The main differences between left and right fielders are, first, that left fielders handle more chances because right-handed pull hitters tend to hit balls to left; second, that right fielders typically have stronger arms; third, that right fielders are frequently (not always) slower and less agile defensively. Many left fielders have had the speed to play center field, but have lacked the throwing ability required.

An example of an ultra-fast left fielder is Rickey Henderson

Rickey Henderson

Rickey Henley Henderson is a former Major League Baseball left fielder who played for nine teams from 1979 to 2003, including four stints with his original team, the Oakland Athletics. Nicknamed The Man of Steal, he is widely regarded as the sport's greatest leadoff hitter and baserunner...

, whereas the slow-footed but very strong-armed Carl Furillo

Carl Furillo

Carl Anthony Furillo , nicknamed "The Reading Rifle" and "Skoonj," was a right fielder in Major League Baseball who played his entire career for the Brooklyn and Los Angeles Dodgers...

, "The Reading Rifle," sets a standard for right fielders in the terms specified here.

Often, when an outfield prospect arrives in the majors, he plays both corner positions before settling at one or another.