hmm.. I've just played a very strange game against XG ('world class' setting). Although he was 2-6 down in a 7pt match, he never doubled me at any stage. I've never seen this before from a bot. Whilst he had nothing much to gain - except the possibility I might have a brainfart and drop a winning position - he had nothing much to lose either.

I remember back in the days I used to play gnubg, he would berate me fiercely if I didn't double on move 1, and would have me firmly in the Cretin Class if I still hadn't doubled by move 4. But is equity _really_ lost each time you don't double? Should you jump into the pit at once, regardless, or wait until there's at least a faint glimmer of a soft drop?

When I've been down in a match vs. XG and auto-doubled at my first post-Crawford opportunity I don't ever recall that decision being flagged as a blunder. I can't see how that isn't a 100% standard play.

When did I say that XG marked a first-opportunity auto double as a blunder? Try reading my post again.

Yes, XG does this on WC. I think XG Roller doubles straight away. Ofcourse for the bot it doesn't really matter, it sees that the value of doubling is exactly 0, not sure why it handles it different on different settings (maybe something to do with rounding).

Post crawford scores where the trailer is an odd number of points away can be interesting if the trailer doesn't double straight away, and you can pick up some equity if you know what you're doing.

Most likely this was in a situation where you needed an even number of points.

Settle down, homie. I'm just saying that when I've been in the same situation as XG was in your match it's never been flagged as a bad play. You can always do a rollout with the score at 2-6 and see what XG thinks of the double.

Kit Woolsey: "4-2 (1 away, 3 away) Post-Crawford...There is a way to potentially gain an advantage against an unknowledgable or unsuspecting opponent if you are the trailer. Instead of doubling immediately, intentionally forget to double. Instead, wait until you have a very strong (but not gammonish) position. Now turn the cube. As the previous analysis shows your opponent should take, of course, almost no matter how bad his position is. If your opponent makes an error and drops, you have essentially won a free point. This may seem like a silly ploy, but I have used it successfully many times, often against quite competent opposition. Note that if the position starts to get gammonish it is now necessary to double. If your game becomes so strong that it is more likely you will win a gammon than lose the game, it now becomes correct for your opponent to drop. Until there is a danger of that happening it is safe to wait, giving your opponent an opportunity to make an error when you finally double." http://www.bkgm.com/articles/GOL/Aug99/fivept.htm

And if you loose the game, you have nothing lost by not turning the cube, because you lost the match anyway. But you can steal some equity, when your opponent drops, when there ist not the free drop situation (free drop at even numbers of points behind). Reading the old guys can help a little bit. In the interview on the Phil Simborg homepage, Matt Cohn-Geier said also, reading the Five-Point-Match from Woolsey helped him. As we see, buying just XG isn't holistic.

@ Mute / higonfive ~

Thanks - interesting stuff!