Analysis of the frequency of dropping numbers
As the name suggests, (by the way, Americans call the tracking method) this strategy deals with tracking and analyzing winning combinations over a certain period of time.
Numbers, falling out more often than others in a certain lottery can be conditionally called "hot". Some players bet on them, based on the assumption, that since they were often dropped in previous draws, then they will probably fall out more often than others in the future. Others vice versa, choose "cold", that is those, which previously appeared less often than others. Still others use combinations of hot and cold numbers., as well as from personal numbers, such, like birthdays and other memorable dates. Sure, lottery organizers themselves also track combinations and strive, to keep the game unpredictable.
Every player, which analyzes the frequency of falling numbers, himself determines, how to use the data obtained and what numbers to bet on in the end. Some players, using this method, in the end win. So, known, that American Jenny Callus (Janie Kallus), which hit the very first Texas Lotto jackpot - 21 million dollars, used dropout analysis, and since she did not have enough data for the Texas Lotto, she used data from other American lotteries.
You can study statistics of various popular lotteries with a sample for different time periods in the section lottery draws.