9x9 go

Normally, go is played on a 19x19 board. However, other sizes occur sporadically, and especially 9x9 is somewhat popular.

(Statistics: one can maybe collect 100000 Japanese pro games on 19x19 and perhaps 1000 Japanese pro games on 9x9. This site has 50000+ 19x19 games, and 500+ 9x9 games played by Japanese pros.)

Minigo

A long weekly series of 9x9 games came from the weekly Yomiuri TV broadcast known as Minigo (ミニ碁一番勝負).

Ricoh Pairgo

For Rico Pairgo there is an intermediate round played on 9x9. (Two rounds are played. The pairs who lost twice are out. The pairs who won twice can continue. The pairs who won once and lost once play an intermediate knockout round on 9x9.) This yields 28 games for 2003-2009.

NHK

Some NHK special events are played on 9x9.

Miscellaneous

Miscellaneous 9x9 events.

13x13 go

In 2014 a Pro 13x13 Tournament was held.

Four 2015 Kansai Ki-in 13x13 2-game matches.

In 2016 a ProAma 13x13 Tournament was held.

15x15 go

In 1964 a 15x15 game Otake Hideo vs. Rin Kaiho was played.

21x21 go

In 1975 a 21x21 game Hashimoto Shoji vs. Rin Kaiho was played.