-For animation, moves should contains "moving" and "fading" maybe...
-Depth 2 or 3 depending on variant and if we detect smartphone or not?
-(static get SEARCH_DEPTH() { return 2; })
+Full detection of repeated positions (including turn)
+In UltimaChess, consider these rules modifications: http://www.inference.org.uk/mackay/ultima/ultima.html