When does Clash of Clans diminish the effectivity of your attacks?

Solution 1:

This might be due to your opponent's king attacking yours first. A level 10 king can defeat a level 13 king in 13 hits while a level 13 king can defeat a level 10 king in 10 hits. The opponent's king strikes first and thus when your opponent's king strikes the 13th time, your king is destroyed and and the other king has around 200 health left, which is 1/11th of the health of the other king. Proof: Clash of Clans Wiki and a calculator.

Your strategy's effectiveness will be determined by the base you raid. Sometimes, bases that look similar to the one you 3 star-ed will actually destroy your troops and make you lose. Try to adjust your strategy to be able to use it appropriately with different types of bases.

This is a huge worldwide sensation. If this was figured out, chaos will sowed and the end of Clash of Clans it is.