Mochikomi

Hasty inside play  

A simple example is the hasty inside play . White can easily escape, making a mochikomi. Black could for example play at 2, force White to defend at 1, and invade at a.

Moves 43 to 46  

This position is from a Yoda Norimoto-Yamashita Keigo game played 2003-10-01 in the Meijin tournament. The three stones in the upper left constitute a strategic mochikomi. Yoda presumably knowingly sacrified the stones, but the point is that he did so (was forced to do so) in a way which left virtually no aji in the position.

End position  

This is the final position.　White won by 2.5 points.

Hayashi example  

This tactical mochikomi example is from a Takagawa Shukaku-Fujisawa Hosai game. was an oversight, and after White has turned Black's stones into a mochikomi (one could say in English, has "orphaned" them; in Japanese, mochikomi ni shita).

Shojiten example  

In this example, from the Nihon Ki-in's Hayawakari Yougo Shojiten, and turn into a tactical mochikomi.

Hamete example  

This example is from "Shin Hayawakari Hamete Shojiten", also published by the Nihon Ki-in. It comments that after the hamete sequence shown here, is now mochikomi (mochikomi ni natte-iru, p. 164). (The hamete was initiated by the marked Black stone. The refutation is to play rather than . For extra credit, what is Black's follow-up move?)

Anon: The follow up is at a.

The English phrase "failed invasion" is sometimes used for mochikomi, a translation which is accurate to the extent the term invasion is given a broader meaning than the Japanese uchikomi, to include a variety of inside moves, reductions, or even monkey jumps. For instance, to the extent in the second diagram above is considered an "invasion"--which it might well be by some Western players, although in Japanese it would not be called uchikomi but instead oki (placement)--it is indeed a "failed invasion". However, if the term failed invasion is wrongly interpreted as being limited to a "typical" invasion--in the middle of a moyo, perhaps--the broader meaning given at the top of this page can be lost.