Tzaar is a great game. Yinsh is strongly worthy of recognition. Of the Gipf games, these two and Dvonn, in my opinion, deserve to be regarded as enduring modern classics. I agree that it would be nice to have all three on LG, and I have made the suggestion before. In the meantime, there is another turn-based web-play option for Tzaar and Yinsh, which I enjoy.
