Zelandakh, on 2013-September-09, 07:31, said:
First, it becomes much easier for us to compete in the auction. There are many hands where I'd overcall at the one level but it's too dangerous to overcall a level higher over strong notrump. This can help with leads as well as buying the contract. Sometimes we create issues simply because opponents are left guessing whether opener had a strong notrump (i.e 1C-3S and you hold a ten count 3352; probably opener has a strong notrump so maybe you bid 3nt, but if opener has an unbalanced 12 this can easily be a huge disaster).
Second, when opponents bid to a normal spot I find that I have a much better picture of opener's shape (if only because he told me his 4-card minor) and that this makes the defense much easier.