High Vs Low Pincer

Pincering the high approach  

Ishida's Joseki Dictionary considers only four pincers in this situation a through d. I believe that it is most reasonable to consider a a special case. The point of a is the threat to connect under at e. Otherwise low pincers tend not to pose much of a threat to White since the One space high approach stone itself is light.

Pincering the low approach  

The situation is more complex when we turn to the low approach move. Partly this is historical - the low approach was standard for hundreds of years in Japan and much of the current codified joseki derive from that history. We can find all of a through f in the dictionaries and recently we can see the use of g as well. Historically, a low pincer was the weapon of choice against the low approach stone. I think this is natural. The low approach is fundamentally 'heavier' than the high move by virtue of being deeper in the opponent's area of influence (even if that area is no larger than the corner stone and the pincer). One of the natural escape routes for the low stone is to slide down the side away from the corner. All the low pincers close or at least limit this route.

All of the high pincers are modern moves, basically developed during the twentieth century. They are more concerned with rapid development and overall balance.

The Relation with the Lower Corner

When I choose a pincer in my own games I normally think hard about the lower corner - is it mine or my opponent's, is the position there open (for example a 4-4 stone) or closed (e.g. a shimari)? If the left side is the focus of the game, my rules of thumb:

• From my own hoshi (4-4) stone play a high pincer or a tight pincer. The corner is still open and later a shoulder hit against a low pincer may erase any potential territory on the side. The point is to put pressure on the opponent and expect to build influence rather than territory.
• From a shimari play a low pincer and try to make territory in front of the shimari.
• From my opponent's hoshi stone think hard about how to handle a counter-pincer - it will probably show up sooner rather than later! A high pincer will allow a light response to a counter-pincer - perhaps a capping play followed by invading the open 3-3 point.
• From my opponent's shimari - consider how to extend down the side from the pincer before the opponent's counter-pincer appears. The corner is already closed so the issue is who gets how much along the side.

What are your rules/favorites?