&gt; You cannot cleanly make lines with only s-pieces.<p>That&#x27;s not true at all.<p><pre><code>  |   |   |   |
  --  --  --  --
    |   |   |   |
</code></pre>
Sorry for the bad ASCII art, but I just created a line using only &#x27;S&#x27; pieces.  When the line clears, the top of the &#x27;S&#x27; will collapse and clear a second line.