So I just enjoyed my most spectacular single-game victory over GNU in the form of a 24 point backgammon with the cube at 8. Regrettably, the cube error I made in the following position has thrown a wet blanket over the whole affair:


For a fleeting moment, I actually had the gall to wonder if I might be too good to double! But what opponent would not even consider accepting the cube from this position? So by Woolsey's Law, I redoubled.

That, as it turns out, was an error. And not because I was too good to double, but because I wasn't good enough! GNU graded this a -.091 error even while giving me a 73.6% chance to win.

Never mind that I rolled a 6-4 and snatched GNU's wretched soul. My victory is tainted and I don't understand why.

In a money game this would just be redouble and huge pass.

But you're leading in the match and that changes everything. Back in the day we used to call these positions "too good/not good enough". You have too many gammon chances (26% or so according to XG), so you play on and try for a gammon which would take you to 1-away 7-away Crawford. Your opponent then needs to win four in a row (three if he can squeeze a gammon in there somewhere) to win the match.

If you hold on to the cube and just win the game, you're up 3-away 7-away, and you didn't put the whole match at risk, so that's fine.

But if you double, your opponent takes and rewhips to 8 whenever he gets a shot. You'll take, of course, but now the whole match is on the line (and just look at your opponent's board!) You don't want to give him that chance with a lead and a gammonish position. So just keep the cube and play the game out.

It is as though, in your last paragraph, you see my past in an inverted crystal ball. That is precisely what came to pass, but summatively and formatively. Match score dynamics and the influence of gammon potential are both areas I need to develop. Unfortunately, they conspired against me here.

On the bright side, there do exist circumstances under which my decision to redouble would have been correct, lol. Thanks for your thoughtful (if not clairvoyant) evaluation.

*both* summatively and formatively.

You might find my posts in this thread helpful:

https://forumserver.twoplustwo.com/1...09/?highlight=

Yes, that's a good thread. Much more interesting than arguing about which online site uses rigged dice!