There is so much great material out there for 19x19 as it is the main size board. I play with a group of people and we use a 13x13 (mainly to keep games shorter as it is always during our lunch break). Are there any 13x13 resources out there (lectures, videos, etc)? Perhaps a more experienced user who plays 13x13 could point out a few things that make it different than 19x19/general principles for opening moves especially.
I’m not an “expert”, but to me 13x13 differs from 19x19 especially in how players should manage the middlegame and the late opening stage.
The first steps of the opening are quite similar: take corners, then take enclosures/corner approaches, then extend to the side by 4-5 spaces (if there are no bigger moves on the board).
In 13x13 games I don’t see enclosures very often, as usually corner approaches are also extensions from one’s corner, so approaches seem to be more efficient.
Especially approaches to opponent’s 3-4 stones facing one’s 4-4 stones are really good, as the 4-4 usually stands exactly “in place” for most josekis, so if you choose to approach a 3-4 with a variation that ends in gote on 19x19, on 13x13 you end in sente instead (because your 4-4 is already there).
Also, be careful when you choose a joseki: some 19x19 joseki are good in certain situations, but given the smaller board, situations are different.
I don’t think I can give you any other advice, as I don’t usually play 13x13. And I don’t know if there’s some go literature about 13x13 around…
Thanks, that was extremely helpful