There is a saying in baseball that no matter what position you play, there is a place for you to be on every single play. One such place for a second baseman is to back up first base on certain throws to that base. Here’s an example: With nobody on base, a grounder is hit to the third baseman. Because they are not directly involved in the catch or throw on the play, many second basemen just become spectators and watch the play proceed. They may instinctively step to their right when the ball is hit but after that, many just stop and watch. This is a bad habit to get into.
When a 2nd baseman is not directly involved in the play,
he should be moving towards 1st base to "be in the area"
for bad throws.
A second baseman probably will always react to the batted ball by moving a step or two to his right but what he does after that is certainly under his control. After his initial jump to the right, a second baseman should then sprint to the first base line. In reality, he will never be able to back up the throw to first base directly. Sprinting towards the line will, however, put him “in the area” in case a throw should get past the first baseman or deflect off his glove.The average fan may not notice what the second baseman is doing (or not doing) on this type of play. They are usually watching the ball. Scouts and coaches, however, pay close attention to those things because it gives them clues about the player's hustle, instincts, and knowledge of the game.