@Brian-E said in #5:
> If you play Bent Larsen's 1.b3 watch out for this pitfall:
>
> 1.b3 d5 2.Bb2 c5 3.Nf3?! f6! followed by ...e5 and Black has set up a virtually impregnable pawn centre which renders the b2 bishop, which White has spent two precious moves developing, almost useless. 3.e3 is correct, transposing into a sort of reverse Queen's Indian, so that then 3...f6?! can be answered by 4.d4.
>
> Having said that, the dubious line has been played in a few master games before.
Fischer played a great game in this line
lichess.org/zkKLicVo/black#132 .