I am following English premier League and Australia A league. 80-85% matches 1st half Happen corner over 3.5 that's odds 1.32-1.40 . So anyone wants to safe betting then you can bet there. Not all matches. Select for a team like Manchester United. If Manchester United and it's partner fail to cover 3.5 corner in 1st half in a match then the next match stake high between Manchester United Vs opponent team. That's the simple tricks. This tips dose not work for 100%, so bet your own risk.
Your post is contradictory, because firstly you mentioned the strategy as a safe betting method, but on your last phrase you say this tip doesn't work 100%. It means the strategy may work or not, like any other we can make use of.
Anyway, it's an interesting concept that can be useful for some gamblers as a start point to develop their own betting patterns, by improving the one shared by you.
It is the same old story, while there are many that enjoy gambling for what it is, which is nothing more but a form of entertainment, there are others that want to make out of it a profession, and in order to do that then there is a need to create a method that earns money while they gamble, but taking into account that the expected value we have on each bet is negative this means that the only way to win, at least when it comes to sport bets, is to find markets that are priced incorrectly, and this incredibly difficult as this will require massive amounts of knowledge and information that the average sport bettor simply does not have.