Conventions are part of the game and bridge wouldn't be nearly so much fun without them. Some conventions, such as
Stayman, Transfers and Blackwood, are considered as fundamental basics and an integral part of bidding, while others are
so esoteric that the ACBL only allows them to be played in special events.
Treatments are different from conventions, although many players think of them as the same thing... If you have an agreement that an opening bid of two diamonds shows five hearts and four spades you are playing the Flannery convention, but if you play that the bid is a diamond suit with opening point-count then you have a treatment. The difference is that a Flannery two diamonds call is artificial while the other is natural, (you really have a diamond suit) but the bid has a different point-range than the standard treatment. Both bids are alertable because the opponents are expecting a weak two bid in diamonds.
Conventions and treatments also evolve as players use them and find ways to improve them, while others are simply discarded after they are found to present more problems than they solve or do not work very well. And how many times have you heard someone say, "That's too difficult to remember!"
I would like to show you some problems with a few very popular conventions or treatments, and hopefully offer a better way... Also, I would like to ask that if you have found a problem, or maybe a better way for any of our current agreements, please send it to me.