Bunt Defenses in Baseball - Getting the Out at Third Base

The video tutorial explains a baseball play scenario with a runner on 2nd base. It details the roles of the first baseman, third baseman, pitcher, second baseman, and shortstop. The first baseman plays shallow and charges the ball, while the third baseman stays at third to receive throws. The pitcher covers the third base side, and the second baseman backs up the first baseman. The shortstop covers second base. The main goal is to secure at least one out, preferably at third base.

What should the shortstop do when the second baseman runs to first base?

How does the first baseman's positioning change when there is no runner at first base?