These patterns are harvested from the GoGoD (Go Games on Disk)
2008-Winter collection, scanning all games in the collection.

Furthermore, moves from KGS handicap games were scanned when
they have met the following criteria:

  * Games played between 2007-01 and 2011-10, with the white
    player 4d or stronger: http://u-go.net/gamerecords-4d/
  * Only games with 4 to 9 handicap stones were considered.
  * Only moves made by white have been included.

Furthermore, moves from KGS handicap games involving Pachi
were scanned. No restriction on handicap stones has been placed,
but only white moves in games where Pachi was black were included;
this is to allow Pachi expect common refutations for situations
it likes to create. Games from accounts pachi, pachIV, pachIW,
pachi2, pachi30s, pachiichi, pachini and pachishi were used.

Only patterns occuring at least twice have been stored.