If playing second, I very often lay a tice just off the North boundary, aiming from the end of B-baulk towards the point 1 foot South of corner 2, but stopping about 1-4 yards short of the corner depending on how good a shot I think oppo is (and how well I judge the pace of the lawn). Compared to West boundary tices or duffer tices, this one always leaves a close double if the 3rd ball shoots and misses (unless it's a really bad shot). This makes oppo reluctant to shoot at it. The main downside is that if 3rd and 4th balls both shoot and miss, oppo gets a very easy start.

I don't think I've ever come [across] what I would recognise as a refutation of this opening.

Why isn't it more popular?

I play this kind of tice occasionally and one of the downsides is that the target the opponent leaves is rarely a perfect double. A miss on the right often leaves something close to a single ball. A miss on the left doesn't need to be by that far before the target has a hole in the middle (particularly if the tice has wandered further south than ideal).

On the whole I think the Duffer tice is better. The Duffer is more dangerous for the oppo to ignore and join partner and more dangerous to shoot at directly.

The tice towards corner 2 is useful in that you can lay it without giving much help to the opponent in going round third turn e.g. as a response to an anti-Duffer.

Good point that if the north boundary isn't flat, it can go a bit wrong. E.g. the tice itself wanders into the yard line area.

In terms of leaving or not leaving doubles, if I aim towards the same spot that people sometimes use in response to a Supershot opening, then - apart from lawn irregularities — I should have the same chance of a doube as if I had gone all teh way to the boundary.

Yes, the best refutation of any tice is to hit it. The interesting thing about this tice when I've played it is how few people do actually shoot at it. If they've opened on the East boundary they tend to join partner, either wide or close. But of course most of my opponents are not at the top level.

In both of your emails on this topic you mention, as an apparent benefit of this shot, that relatively few people shoot at it. This rather flies in the face of calling it a tice, the whole point of which is to entice people to do exactly that: shoot at it!

On a simplistic interpretation of "tice", this is true, but of course there is more to tice theory than that.

When I lay a tice, there are usually two desirable outcomes that I have in view: (a) oppo shoots at it and misses, leaving a position that is favourable to me, or (b) oppo declines to shoot at it, leaving a position that is favourable to me. By "favourable to me", I mean that I have an easy shot (short, or a double), or can safely join up, or both.

Of course the risk is that (c) oppo shoots at the tice and hits. Therefore the tice should be placed so that the chance of (c), or at any rate the chance of oppo's getting a break out of it, is acceptably low.

(There is also the risk that (d) oppo declines to shoot at the tice and obtains an outcome unfavourable to me — usually by shooting at his own ball and hitting. But that risk exists regardless of what I do with my ball, unless I shoot at oppo's ball in turn 2 and move it to a position that favours me more.)

It could be argued that "tice" is the wrong word for this, but it's the word we're stuck with, and so long as everyone understands that the above reasoning is implicit in the notion we're OK.

For a standard (west boundary) tice, yes — it's in [Keith] Wylie if I remember rightly.

For a duffer tice, a shorter distance is optimal, because oppo gives more away by shooting and missing, and is therefore likely to be dissuaded from shooting if the chance of hitting is only 50% or even if it is slightly higher. The same applies to Rob's north boundary tice, if it's placed successfully to give a high chance of a double from a miss.