The reason the deuces wild game pays more is because a deuce is not normally as valuable as a seven. This is because there are more ways of making straights and straight flushes around a seven. So making deuces wild is a bigger change than making sevens wild. As I show in my section on Anything’s Wild under the same pay table making deuces wild has a return of 96.76%, while sevens wild is only 94.13%.