Situation 1: 4-g at the B-8. FG is blocked and recovered by team A at B-12. The ball never crossed the LOS.
Situation 2: 4-G at the B-15. FG is blocked by B1. The ball carons to the B-13 where B2 catches the ball and drops to a knee.
I believe both situations should be spotted for a first down for B at the dead ball spot. I wasnt positive...we spotted both at the B-20. Crew discussion "it wouldnt make sense to penalize B for blocking the fg..."
In 1), assuming Team A recovers the ball and is "downed" a that point, then Team B is awarded a series at the spot of the recovery by Team A (dead-ball spot. The must cross the NZ for rule 8-4-2-b-1 to be in effect. If Team A recovers the ball while on their feet, the ball remains alive and in play, and the ball may be advanced. However, being 4th down, they must reach their line-to-gain to retain possession. If they fail to reach their line-to-gain, then Team B is awarded a series at the dead-ball spot ("turnover on downs").
In 2) Team B is awarded a series at the dead-ball spot (where B2 drops to his knee after catching the kicked ball). The ball must be untouched by Team B for rule 8-4-2-b-1 to be in effect.
Team B isn't penalized in either case. In 1), this is no different than if Team A fumbled behind the NZ - both teams have equal opportunity to recover the ball and advance it. So, Team B should have no expectation of getting the ball at the B-20. In 2), all Team B has to do is leave the ball alone, and they'll get a series at the B-20. They get rewarded for leaving the ball alone.