It depends, in little league, the shortstop is the rule. Usually, the shortstop will cover for a left handed hitter, and the second baseman will cover for a right handed hitter.
Because If Shortstop got the ball 2nd would be there to get him out
This position is called shortstop. They act as a cut-off form the outfield on plays that require a relay. They also usually take the throw from the catcher to second base to tag a runner stealing the base.
Shortstops have one main duty, fielding balls hit to their position. When a fly ball is hit to them(either a line drive or pop-up) the player has to catch it, making sure that they don't collide with other fielders trying to make the same play. When a ground ball is hit to them, a shortstop has to throw to a base to get a runner out. Shortstops also cover second base for double plays when the ball is hit to the second baseman. Finally, they(or the second baseman) cover second base on a steal or pick off attempt.
the shortstop
That situation sounds somewhat similar to what is called the rotation play or wheel play in bunt situations. During a bunt situation, usually the first baseman and third baseman cover the bunt while the second baseman will cover first base and the shortstop will cover third base. In the situation you describe it sounds like the shortstop would be the defensive player to cover third base.
Pitcher, Catcher, SHortstop, SEcond Base, THird Base, First Base, Left Field, RIght Field, and Center FIeld
That would depend on 'who' is trying to throw the runner out. This answer will assume the questioner is asking about a stolen base and the 'who' is the catcher. The defensive player that covers second base on a steal attempt is the player that the defense believes is on the side of the field that the ball will NOT be hit to. Factors that go into this decision are whether the batter is righthanded or lefthanded, where the pitcher is going to pitch the ball (inside or outside), and how good of a batter the player is (whether they can hit the ball to all fields, whether they are a pull hitter). Generally, if the batter is righthanded and the pitcher is going to pitch inside the odds are better, if the batter makes contact with the ball, that it will be hit to the left side of the field. In this case, it will be the second baseman's responsibility to cover the base if the runner attempts to steal. If the batter is lefthanded and the pitcher is going to pitch inside the odds are better, if the batter makes contact with the ball, that it will be hit to the right side of the field. In this case, it will be the shortstop's responsibility to cover the base if the runner attempts a steal. The decision of who will cover second base on a steal attempt is made before every pitch. On one pitch the second baseman may be the player to cover and on the next pitch the shortstop may be the player to cover. If you are at a game, you may notice when a player is on first base that the second baseman will put his glove up to his face and look at the shortstop just before a pitch is made. The second baseman is giving a signal to the shortstop as to who will cover second base on a steal attempt. Usually, the signal is an open mouth or closed mouth. If the second baseman looks at the shortstop and his mouth is open, this means the second baseman will be the player to cover if a steal is attempted; if the mouth is closed the shortstop will cover. Or vice versa ... it all depends on how the team has set up their signals.
As a shortstop player myself. A shortstop is like the captain of the infeild. He must let his outfeilders know how many outs there are. If a ball is hit anywhere in the outfeild inside the park and nobody on base the player becomes the cut off man to second base. If there is a runner on first and the ball is hit to the gap for a double the shortstop lines himself up to make the cutoff to third base. If the ball is hit shallow and there is a runner on first the shortstop is the cutoff for second base, same with a runner on second and the ball is hit shallow. If there is a runner on second and the ball is hit to the gap the shortstop goes to cover third base as the third baseman becomes the cut off man but if there is a need for a double cut off the shortstop goes out to be the first cut off who thne throws it in to the second cutoff and if there is a play at home he would throw the ball to home if not he would look to see where the runners are and make sure they stay at their bags.
shortstop
That is the baseball or softball fielding position between second and third base.
Catcher Pitcher First Baseman Second Baseman (Plays between first base and second base, not on second base) Short Stop Third Base Right Field Center FIeld Left Field