Bidding is not an exact science and no bidding system will always lead you into the right contract all the time.
No doubt by now you will have seen some of the snake-oil sellers with their promises of great advancement at the game if you play such-and-such a method or adopt so-and-so's bidding conventions. The shops are full of bridge books on bidding with alluring titles and covers.
Claptrap. Baloney.
Some books are worth reading. Most should be ripped up and used for bonfires. What is more important than system is JUDGEMENT. Essentially - how much is my hand worth now, in the light of the bidding? Sometimes you want to upgrade your hand and sometimes you ought to downgrade it. Let's see what you think here...