I find answer too , Its TZ (Test Zone ) Search that is a combination of Diamond and raster search. Now I need to understand basic algorithm of these two searches and its implementation in HM 14
What's the main paper for TZ search? I am looking the main/original paper for TZ search, but I am getting some derivative papers (e.g. Improved or Enhanced). Can anyone please share the link for the main paper for TZ search Thanks.