Gabriel,
I don't think I'm an expert Bottom Dealer but since you asked for my opinion, here is it:
You're obviously struggeling with extracting the bottom card. There can be several different reasons for that but I assume it is a combination of a lack of (proper) practice and issues of the grip that you're using.
If I'm not mistaken you're doing a strike bottom deal (due to the angle I can't tell if there is a slight buckling action). For a strike bottom deal your middle finger is pretty close to the edge of the deck which makes it difficult to extract the bottom card. I would suggest to move the middle finger a little bit closer to your index finger and away from the edge. That way there will be more room for your right middle finger to extract the bottom card. Moreover, try beveling the deck a little bit (as if you would do a second deal). This also makes it easier to deal the bottom card and (in my opinion) the deal looks less "stiff".
Regarding practice. Try the following: Sail four tops but each time you make contact on the bottom card with your right middle finger. On the fifth card, you now apply pressure to the bottom card and extract and sail it. With the strike bottom deal that you're using, you can make the bottom and the top deal look almost identical. The only thing that changes is that when you want to deal the bottom card, you apply pressure with your middle finger. On the regular top deals you make contact with the bottom card but you do not apply pressure to it. Do this drill very slowly. Video tape yourself and make sure that you maintain a consistent rhythm.
Hope this helps.
Joey
