Game 1, move 8, The Herd: take decision?

[Zorba]

dorbel doubled to two, do we pass or do we take?

XGID=----aBC-C-B-eC-a-a-cbAb-A-:0:0:-1:D:0:0:0:5:10
GNUBg Id: zE7iAwSwc8YBIg:EQGgAAAAAAAA

[stog]

Spoiler

if that's his double 1 in the picture- i'd say "drop", otherwise let's take it!

[close]

[RickrInSF]

Spoiler

I think this is certainly a take, although he has threat - 6 2, 6 4, or 4 2 - 1 out of 6 - if he doesn't get one of these, he will most likely hit 2, 4 or 6 and we have chance to hit back, but i always take too much

[close]

[ah_clem]

Spoiler

Position, race and threats. If he has an advantage in two, it's double-take and if he has an advantage in all three it's double-pass.

Race? - check.
Threats? - you betcha
Position? - three point board vs 2 point board for us. Two checkers back vs three checkers back.  It's not overwhelming, but it's better than what we have.

Looks like three for three.  Pass.

[close]

[Zorba]

As far as "position" goes in the PRAT analysis, let's not forget that dorbel has blots on the 8 and 10pts, whereas we have a made 8pt and 10pt that combine very well with the made 6 and 5pt, and dorbel's backman on our 4pt, plus we have very well placed spares on our 8 and 6pt.

[diane]

That 1-1 was making me nervous too!!                         

As it happens, I am a pass too - this looks scary, I want out, brush myself off and try again with a new start.

The position just now might not be too much in dorbels favour - but he is about to roll and move and then it has the potential to get a whole lot better for him right now.

PASS

[sixty_something]

first, my brain is toast .. second, scrolling down i couldn't help but notice an answer NOT behind spoilers .. so, i tried to use the GNUbg ID to just look at the problem with a more familiar interface and run an analysis on it .. however, the ID failed to produce the correct position/situation

did you forget to update the ID, Zorb, or is my toast burned

[gumpi]

Spoiler

Dorbel´s short of attackers, 3 blots dangeling arround. We have the 5 and nice structure: Take

[close]

.

[blitzxz]

This looks classical wrong take position. Serious gammon threats combined with good race lead is a drop in this score. Gammons take dorbel to crawford game and almost sure win. I don't even care if I would found out that bots say this is a take. I would still drop it. I never want to lose a match this fast. 1-0 is still almost equal. That's good for me. This is not worth the risk. PASS.

[ah_clem]

As far as "position" goes in the PRAT analysis, let's not forget that dorbel has blots on the 8 and 10pts, whereas we have a made 8pt and 10pt that combine very well with the made 6 and 5pt, and dorbel's backman on our 4pt, plus we have very well placed spares on our 8 and 6pt.

Agreed, and that's what makes this a hard decision.  I see his position as being better, but not by a huge amount.  So we have maybe 2.3 out of the PRAT trinity.  That puts it on the borderline between take and pass.  What tips it to pass for me is the gammon chances - there are too many ways for this to go terribly wrong for us - without an anchor, any hit/dance is a one-way ticket to Gammon City.

All that said, I think it's a close decision, and a take is reasonable.

[ah_clem]

... scrolling down i couldn't help but notice an answer NOT behind spoilers .. so, i tried to use the GNUbg ID to just look at the problem with a more familiar interface and run an analysis on it

We seem to have defaulted to putting the first response or two behind a spoiler to prevent an unintended read when looking at the diagram.  Once we're three responses into the thread the spoiler is much less necessary so some of us have been dispensing with it.

As for gnubg analysis, you shouldn't be using the bot until after the voting is over.  Agree that the picture is a bit blurry this time...

[RickrInSF]

I only have one suggestion 60, if you ever plan on playing bg in a tournament or simply on a board, get used to the other direction.

As for me, i didn't know about the "custom" of not putting spoilers as spoilers after third post, but i will always use them just for you   

[Zorba]

XG double/take rollout:

Spoiler

Some people have something to think about... monster take, and not even a double actually. Given the many passes, a good practical double though, Looks much scarier than it really is: we're not even on the bar here, it's just a three point board and dorbel's short on ammo. Besides, we have an excellent front position to fight back.

No Double
  Player Winning Chances:    59,81% (G: 22,48% B:  1,16%)
  Opponent Winning Chances:  40,19% (G: 10,08% B:  0,63%)
Double/Take
  Player Winning Chances:    59,81% (G: 23,67% B:  1,33%)
  Opponent Winning Chances:  40,19% (G: 10,38% B:  1,06%)

Cubeless Equities: No Double=+0,315, Double=+0,713

Cubeful Equities:
       No Double:   +0,471
       Double/Take: +0,409 (-0,062)
       Double/Drop: +1,000 (+0,529)

Best Cube action: No Double / Take

Rollout
  15552 Games rolled with Variance Reduction.
  Moves: 1 ply, cube decisions: 3 ply Red
  Confidence No Double: ± 0,007 (+0,464<E<+0,478)
  Confidence Double:    ± 0,010 (+0,399<E<+0,419)
 
  Double Decision confidence: 100,0%
  Take Decision confidence: 100,0%
 
  Duration: 1 hour 27 minutes

eXtreme Gammon Version: 1.14, MET: Rockwell-Kazaross

[close]

[Zorba]

I can't believe how many people wanted to drop this, quite shocking. From the comments, it sounds like fear played a big part here, probably most of all, the fear of losing 4pts in one game. Nobody mentioned all the bad rolls dorbel had, and how quickly we could turn the game around and offer dorbel the dreaded recube to 4! Only gumpi mentioned that dorbel had just 9 checkers "in the zone" (i.e. ready to point/hit loose in a blitz), the rest were still sitting ineffectively on dorbel's midpoint. The most likely result is that even if dorbel rolls well, we can still anchor. If dorbel doesn't roll well, we're usuallly just slight underdogs. A loose hit by dorbel where we return-hit and we're instant favourites. A complete close-out with huge gammon chances is difficult to achieve for dorbel from here.

Anyhow, for blitz cubes like this, it really pays off to have some reference positions, and  I like to use the one that results from a 24/22 split in the opening roll, then opponent rolling the joker 5-5 to point on both men. Depending on whether you enter zero, one or both men from the bar, and a few other factors, you got all the double/take decisions right there and there's some fairly easy patterns to learn.

Going from there, you can then try to adjust for other blitz positions. A three point board blitz with one checker on the bar can still be a take, depending on other factors. With two checkers on the bar it's a clear pass. With zero checkers on the bar, as in the actual position here, it's a huge take.

[stiefnu]

Only gumpi mentioned that dorbel had just 9 checkers "in the zone"

Having more than 8 checkers in the zone is surely enough to put one into a blitzing position?

[Zorba]

You can blitz with pretty much any amount of checkers, but the number of checkers "in the zone" plays a huge part in determining how succesful you're gonna be, and thus, whether a position is a double, a take or a pass.

9 checkers in the zone is just one man extra from the midpoint and can make at most 4 points.

With no checkers on the bar for us and facing a three point board, dorbel's army of 9 isn't very impressive which is why it's such a huge take. If dorbel would've had two extra men down form the midpoint, even if not completely in the zone, things would look much different.

[ah_clem]

Is there a standard definition of "the zone"?  I'm assuming that a checker has to be within a direct shot of a homeboard point to be in the zone, but maybe it's more subtle than that....

[Zorba]

http://bkgm.com/glossary.html#Z describes points 1-11 as the zone. I guess you could then call the area in direct range of open points you need to close, the "hot zone".

It's interesting that in the above link an amount of 10 checkers in the zone is mentioned for a good blitz. That's of course just an indication. We all know you play many 5-5 opening replies to opponent's split backcheckers, as a blitz, even if you have only 8 checkers in the zone. It depends on how many checkers you put on the bar, how an alternative move looks, how easy it is to get extra troops in the zone, and what liability there is in not developing your backcheckers for a while.