Need your opinion

[Bluefoot]

I undestand your thought process, but a BR can only be put out between home and 1B if the BR is trying to avoid being tagged out by the defense.

The retreat to the previous base (1B), as you describe, is allowed, and the rule mentioned above does not apply.

I learned it a few years ago when I had a game with R1 on 2B and R2 on 1B no outs. BR3 hit a grounder to F5 who scooped it up and started to run at R1 who was halfway between 2B and 3B. R1 started to retreat toward 2B, and I called R2 out for retreating, just like you also thought. I looked it up after the game and wrote about it here, and learned that I had it wrong.