Talk:Blazing Phoenix Feng/@comment-29643927-20170223183101/@comment-26947994-20170316224719

The chance for reviving using both buffs is actually 20.8%. This is because there is a 90% chance of not reviving for Feng's SBB, and a 88% chance of not reviving for Juno-Seto's SBB. Multiplying these together gives a 79.2% of not reviving, which gives a 20.8% chance of reviving. This method of calculating something is called complementary counting; you find the probability that you don't want, and subtract it from the total probability (100%).

Adding the percentages together gives the expected value of a revive, or that a revive buff will occur 22% of the time. However, this double counts the probability that both SBBs revive the unit, because that probability counts when there are two revive buffs. Because this probability is doubled when you add it, you have to subtract 1.2% (probability of both SBB reviving) from 22%. This uses a concept called PIE, or the Principle of Inclusion and Exclusion, helpful for counting things once, and only once.