Perty good, wofa. Onliest thang, the third baseman is 5 and the shortstop is 6. Ya see, originally the shortstop was an outfielder or at least, sort of a transitional infielder/outfielder. Thus he gets the number 6. Nowadays he is strictly an infielder; he and the second baseman share the guarding of second base shifting left and right depending on the hitting tendencies of the batter. Together they are referred to as middle infielders. The numbers are used to indicate the passage of the ball from one fielder to another. The most common infield outs are hit to either the second baseman or the shortstop. With a runner on first the middle infielder fielding the ball throws it to the other who makes the out at second. After that it is pretty much the way wofa described it. That the play at second has to be made before the play at first is due to fine details in the rules of baseball and can result in a 3-4-3 double play.
(you got the outfielders in the wrong direction too, wofa)
