Following feedback from their use in various international tournaments , extensive reviews took place prior to the issue of version two in November 2010 , which was used at the 2011 World Scrabble Championship in Warsaw , Poland , and other international events such as the Causeway Challenge .
Following feedback from their use in various international tournaments , an extensive review took place prior to the issue of version two in November 2010 . 
 Version two was used at the 2011 World Scrabble Championship in Warsaw , Poland , and other international events such as the Causeway Challenge .