This play depicts how a rundown between 1st and 2nd should be executed.
The key is to make sure that the runner does not advance so the throws from the originating base are made earlier than the throws from the advancing base.
The defensive fielders will chase or run down the runner and then progress to the base to back each other up. This can be practiced as a drill without a runner to get the players use to throwing to each other on a run and backing up the base.
The Pitcher throws to 1B picking off the runner on 1st base during a steal.
The runner goes to 2nd base
SS covers 2nd base and
2B backs up SS.
1B base throws to SS at 2nd base.
Pitcher Backs up 1st base.
Runner retreats to 1st base.
SS runs down runner.
SS throws to 1B at first when runner is about 2/3rd to 1st base.
SS then runs toward outfield to back up 1st base.
1B runs down Runner who retreats toward 2nd base.
2B covers 2nd base.
When runner is passes about 1/2 way to 2nd base 1B throws to 2B at 2nd base.
1B runs into the infield and then covers 2nd base.
2B runs down the runner who retreats towards 1st base.
2B should try and tag the runner out.
If the runner makes it past 2/3 of the way to 1st base then.
2B should throw to 1st base now covered by the Pitcher to get the runner out.
The runner will either be tagged out or return safely to the base without advancing.
Either case is a successful rundown.