My apologies. I was unclear.
ArcyTheArcanine wrote:
Sometimes it's not worth it because their creatures won't give you back 40 life.
Since SoSac is active for 2 turns, Arcy obviously meant that using SoSac would not be worthwhile if your opponent's creatures healed for less than 40HP
total over the course of 2 turns.
When I explained that only 21HP of healing are necessary to benefit from SoSac's use, I did so within the same 2-turn context that Arcy created. Yes, obviously, this equates to 10.5HP per turn, or 10, rounded down.
Therefore, we're both correct. If your opponent has on the field creatures and weapons dealing a total of 10 damage per turn, you will break even on HP by using SoSac. If your opponent is dealing 11 or more damage per turn, you profit. If your opponent is dealing 21 or more damage per turn, SoSac will deliver more HP than you sacrificed.
I'm not sure what you mean by "win 2 turns". To me, that expression sounds like the game awards you 2 turns out of nowhere. To my knowledge, EtG is not configured to do this.
I think you mean that for the 2 turns that SoSac is active, you may do anything you wish to your opponent, while your opponent is unable to harm you. Is that a fair summary of what you were saying?