Article 34863 of rec.puzzles:
From: hoey@aic.nrl.navy.mil (Dan Hoey)
Newsgroups: rec.puzzles
Subject: Another Tetris puzzle
Date: 29 Oct 1995 06:22:27 GMT
Organization: Navy Center for Artificial Intelligence

Another interesting phenomenon in Tetris is the creation of
unsupported parts--parts that hang in the air without falling, because
their former support has cleared after they were stopped.  For
instance, it is possible to create the following formation with only
six pieces:

  .........x
  x.........
  x.........
  x.........

The distance between the unsupported square and the nearest neighbor
is clearly at a maximum here.  But how far away can you put an
unsupported part if you are restricted to using T-pieces?  What about
the other pieces?

Are there any other measures of difficulty for unsupported parts,
bettter than distance to nearest neighbor?

Dan Hoey                       No follow-ups from persons who refuse
Hoey@AIC.NRL.Navy.Mil          to accept e-mail comments, please.