http://ciisqbg45nggykdl6rjdrq3wc64csga4vkphu66qsi65mypeitqedoad.onion/blog/balancing-loads
At the third rule, there's now a 1 in 3 chance of matching, but 0.2 probability is still being used. If we make it to the 4th rule, there's only two rules left, so a 50% chance of it matching, while still applying the 20% probability.