4 Wishes question?

First of all thanks to whoever recommended this show. Finally one that actually scratches the genius itch. It's sooo good. I think we should have a flair for 4 wishes because it's really that good.

I only watched till episode 2 but I am confused about somethings:

!EP 1: In the strategy to get absolute: why the double -19 and 19 pieces get two attacks hence +2 points each while 38 and 76 attack once and gain only +1 each?!<

!EP2: Why did she add the neodymium magnet to her piece. I thought the pieces are magnetic already? What was the need for the extra tiny magnet she added?!<