Sam Il
Sam Il is another early pattern, mentioned in the 1959 manual, and uses a healthy mix of a few kata. It feels similar in flow to Gankaku, just as Ge Baek did, but does not use any of the sequences found in Ge Baek.
The following videos were used as reference:
ITF Legacy performance of Sam Il.
Hirokazu Kanazawa performing Gankaku, Enpi, Jitte, Bassai-Dai (Shotokan).
Sam Il begins sliding forward, possibly inspired by the (often reused) opening of Bassai-Dai, or possibly meant to be the opposite of Ge Baek. I think it is noteworthy, however, that Sam Il is the only Chang Hon pattern that opens with a jump or slide forward.
Sam Il's hand-on-wrist block is also found in Bassai-Dai, where it is also followed by a kick. Bassai-Dai executes a side kick, whereas Bassai-Sho does a front kick. In 1965, it should be noticed, this movement was done with a front kick.
Sam Il (shown here from the side) then turns to the side and executes a sequence very similar to this piece of Gankaku. It seems to be a combination of Gankaku and Heian Godan (see: Choong Moo).
Sam Il then turns to the other side, again performing an inner forearm wedging block (with the knife hand).
Gankaku follows this with the 180 stepping section seen in Ge Baek, followed by a turn to the side and a similar block.
Sam Il uses this low punch several times, and it is also found in Gankaku.
Sam Il later performs two U shaped blocks, performed stepping forward as they appear in Jitte...
...then does this jump sequence from Enpi, previously seen in Choong Moo.
Sam Il uses Jitte's W shape block stomp (see: Toi Gye), a few other isolated techniques seen previously, and a 180 degree turn into an inward block and punch, resembling Bassai's 180 degree turn into an inward block and outward block.
