Question
Why is it that the Shin on the Tefilin Shel Rosh is written with four branches on one side and three branches on the other side?
Answer
The Bet Yosef in OC Siman 32 quotes sources who explain that the 4-branched shin is because the inscribed letter that would be formed inside this shin would be a regular three-branched shin, and then proceeds to explain; Since any explanation I give will not explain this properly anyway, so you should see it inside.
