only playing the big blind

[cairpre]

I was playing in a sit and go online. I observed that the winner did not play a single hand except as the big blind until it got down to 3-4 players. And then he played pretty aggressively and actually won the tournament.
I thought I would try it, or something like it.
I tried a few sit and go's playing only only the most premium hands A-J paired and A-K suited or unsuited. Except
I would play the button and small blind a little less tight. And I would play very aggessively from the big blind.

This worked pretty well at small stakes. I managed to place in a few events and won one. But I found that I did not win at higher stakes. And that I was often the small stack when things did not go my way.
I guess I would like to know if this is a known strategy
Is its problem against better players a function of its extreme tightness, or will it work if I work on improving my short table and heads up play. Thank you