I posted this in the Korean general forum hoping to get replies from any style. I know the numbering varies from style/school to style/school so for reference I am asking about the Pyung Ahn form where the first move is a double move; a high block and an outside block done together. Which blocking arm to you have on TOP? This came up in a discussion with several BB's last night. All of the longer term BB's immediately said high block on top. Top my surprise, some BB's did not know and some said the outside block. So I am asking the forum; not for just an answer but for the why. Here is mine; the high block is a vertical movement and because of the outside block in play, you cannot twist the body as you normally would so the blocking arm simply travels straight up. The outside block is a "cross-draw", lateral movement so if the high block was on the bottom you could not cross draw, and would throw the high block off its intended course. The Um Yong for the high block is generated from the outside block. Thanks for the input.