Do you think that people can calculate and predict the numbers that machines draw or they're just guessing and picking random number combinations?
Even just playing with numbers that would appear more frequently then others, that doesn't really reduce the number of combinations enough, or in a way it would be in any way profitable to play a lottery. Overwhelming changes are just lose with every bet.
And just ask yourself this: If there would be "sure numbers", why wouldn't people knowing those, use them to win for themselves instead of selling them? Because it doesn't work, that's why.
It just looks cool in a paper to say that technically with this you have a better change of winning. But in reality it's similar to saying you have twice as changes to win with 2 bet then with one bets. And forgetting that with 2 bets your changes are still slim to none. And you can count these "experienced forecasters" as scammers as well, because they know what they are doing is not effective in any way.