the dorbel daily

Friday 6 May 2011

The Big Quiz, part 10

8/2, 6/2, looks obvious and it is absolutely correct. 1 point for that. I made the rather horrid play of 16/10, 13/9, which is consistent with my previous blunders in this game. I seem to have been obsessed with making the points in order and rolling a prime home, but it's a blitz and the way to blitz is to keep making points. How did I play this game so badly is the question that I need to ask myself and it's fairly clear that I wasn't concentrating and certainly wasn't bothering to count shots! Two rolls later I came down to this next position and you won't be surprised by now to hear that I got this wrong as well.

Position ID: bHcYAyBs96YAAA
Score 1-1 to 5, White has the cube and it's Blue to play 6-3. Let's hear why you want to make your play please, every useful to all of us. Until tomorrow, enjoy the game!


ah_clem said...

I see a logic to your play of 16/10 13/9 - it brings a lot of builders into range and you're almost certain to make another homeboard point next roll as long as you're not hit. The thing is, you can make a homeboard point now so why prepare to do something good when you can just do it? I know, 20/20 hindsight and all...

On to the quiz:

There seems to be three reasonable candidates:

1) Hit loose with 10/1

2) play safe with 10/7 9/3

3) play safe with 10/4 9/6

I'm not at all inclined to hit loose against his four point board. If his board were weaker, I'd hit loose and try to play for gammon, but with a solid four prime in his homeboard I'm going to demur.

The other two plays are pretty similar, and most likely fairly close equity-wise. 10/7 9/3 spreads the builders out more, so it should be more flexible. If I was in time trouble I'd just play that based on diversification. But I've got all day to count shots, so why not?

I'm interested in making the 2 or 1 points next turn - which play makes it more likely? I count 20 shakes that make either the 2 or 3 point after playing 10/7 9/3 and only 14 after the other play. Thus 10/7 9/3 is better offensively. What about defensively?

That play leaves blue odd ended, so in theory it should result in more rolls that force blue to leave a shot. Does it? I count 61 and 63 as forcing a shot after 10/7 9/3 while the other play has 61 62 and 65 as forcing blue to leave a shot. Looks about even, so I'm not going to be concerned about odd-endendness.

Play the move that gives better diversification 10/7 9/3.

Steve said...

10-4, 6-3 is also safe with good diversification. Crucially there would then be no bad next rolls, while 10-7, 9-3 leaves inboard blots after 6-1 and 6-3.

Timothy Chow said...

10/4 seems to be the 6 and the question is whether the 3 is 6/3 or 4/1*. The gammon value is close to 1 so that might seem to argue for the hit, to close White out while White still has a lot of pips to come home. If White hits back, she is still stuck on Blue's 1pt, which is difficult to escape from. On the other hand, if White hits back then she has good chances to counterprime. It doesn't strike me as being worth the risk, so I'd play 10/4 6/3.