Would be nice if there was also an &quot;advanced&quot; mode. Only highlight pieces that have less defenders than attackers. And highlight pins.<p>And I assume even more advanced modes highlight perhaps central squares that might be obtained and which open lines. See <a href="https:&#x2F;&#x2F;en.m.wikibooks.org&#x2F;wiki&#x2F;Chess_Strategy&#x2F;Open_lines" rel="nofollow">https:&#x2F;&#x2F;en.m.wikibooks.org&#x2F;wiki&#x2F;Chess_Strategy&#x2F;Open_lines</a> for a nice example.