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July 21, 2012

Justin Post 1

I didn't record any matches from the Novi tournament, but still got one to look at as Justin recorded all of his.  I plan to look at several decisions from this 11 point main event match.

First is a cube decision from the opening game of our 11 point match.  Justin on roll.  Cube action?

is Justin

score: 0
pip: 131
11 point match
pip: 145
score: 0

is Bill
XGID=-a---CD-C-A-bBb--bacbb-B--:0:0:-1:00:0:0:0:11:10
on roll, cube action?

Analyzed in Rollout No double Double/Take
  Player Winning Chances: 71.74% (G:15.75% B:0.76%) 72.23% (G:16.35% B:0.80%)
  Opponent Winning Chances: 28.26% (G:5.86% B:0.23%) 27.77% (G:6.03% B:0.28%)
  Cubeless Equities +0.541 +1.125
Cubeful Equities
     No double:+0.833 (-0.098)±0.009 (+0.824..+0.843)
xg Double/Take:+0.931±0.015 (+0.916..+0.946)
     Double/Pass:+1.000 (+0.069)
Best Cube action: Double / Take
Rollout details
1296 Games rolled with Variance Reduction.
Moves: 3-ply, cube decisions: XG Roller
Double Decision confidence:100.0%
Take Decision confidence:100.0%
Duration: 7 minutes 41 seconds
eXtreme Gammon Version: 2.02, MET: Kazaross XG2
Justing doubled and I dropped.

This result surprised me since the position looks pretty bleak.  Justin is about to make the bar, after which I will be behind a 5-prime not at the edge.

I did a mini-rollout, playing out the position 10 times.  I took Justin's side and let XG play my side.

--------


Based on this mini-rollout the position is a beaver!!

I formed a 5-prime immediately in 9 of 10 games, yet I only won 4 times, getting a total of 8 points.

I lost all sorts of ways.  I lost by getting counteprimed.  I lost when XG escaped my 5-prime.  I lost when XG counterattacked and then escaped the 5-prime.  I lost when XG hit a shot from the deuce point later on.

All in all, I lost 6 times.  Three times I lost 4 cubes. Once I got gammoned on 4 to lose 8 and two other times I only lost 2 cubes, for a total loss of 24 points.

Net, I lost 26 points in 10 games.  While I was clearly unlucky here, at least this let me see the various ways the weaker side can win.  In addition to the ways I actually lost, XG could also get lucky and win the race.
In short, there is much more play here than meets the eye.


July 19, 2012

The triumph of doing nothing

I couldn't resist sharing this chess game from the ICC 5 minute pool.

This Olegas guy is a blitz beast, who was ranked #2 at the time of this game.  I have been on a hot streak lately and being rated ~2400 is really above my true level.  And ~2700 is ridiculously high rated for the 5 minute pool.

Anyway, I was deflated when I saw my opponent for this game.  No chance to win.  I went for a strictly defense strategy.  "I know I can't beat you, but can you beat me?"  Keeping the balance is a legitimate strategy for a slow moving game like chess.  Backgammon is too fast paced for that to work.  Strike first and take the initiative are absolute musts in backgammon. 

This trying not to win strategy can be especially effective at blitz.  You tend to spend more clock time trying to press and win, compared to trying to hold the balanc and not do too much.

Enjoy.

July 14, 2012

KarenDavis

Below are selected decisions from an online match against KarenDavis.

********
7 away 7 away, centered cube.  Me to move 44?
is karendavis

score: 0
pip: 131
7 point match
pip: 135
score: 0

is Chutzpah
XGID=-aBBB-B-B---dB----ccbCb---:0:0:1:44:0:0:0:7:10
to play 44

1.XG Roller++21/17(2) 21/13eq: +0.391
Player:
Opponent:
60.85% (G:10.98% B:0.16%)
39.15% (G:7.59% B:0.18%)
2.XG Roller++13/5(2)eq: +0.337 (-0.054)
Player:
Opponent:
56.27% (G:17.58% B:0.15%)
43.73% (G:5.52% B:0.15%)
3.2-ply21/17(3) 8/4eq: +0.205 (-0.186)
Player:
Opponent:
55.63% (G:12.46% B:0.16%)
44.37% (G:9.42% B:0.23%)
eXtreme Gammon Version: 2.02, MET: Kazaross XG2
I actually got this one right.   Up in the race, race.  Simple!!  21/17(2), 21/13.

************
Next roll.  How to play 51?

is karendavis

score: 0
pip: 127
7 point match
pip: 119
score: 0

is Chutzpah
XGID=-aBBB-B-B---dC---Bbbcab---:0:0:1:51:0:0:0:7:10
to play 51

1.XG Roller+13/7eq: +0.230
Player:
Opponent:
56.58% (G:16.19% B:0.28%)
43.42% (G:12.32% B:0.39%)
2.XG Roller+8/2eq: +0.200 (-0.030)
Player:
Opponent:
55.70% (G:13.00% B:0.20%)
44.30% (G:11.42% B:0.34%)
3.4-ply17/11eq: +0.170 (-0.061)
Player:
Opponent:
55.81% (G:11.26% B:0.35%)
44.19% (G:12.37% B:0.30%)
eXtreme Gammon Version: 2.02, MET: Kazaross XG2
I made the wimpy 8/2.  "No shot before it's time" is the philosophy but this is misguided here.  Karen is getting stronger - I should take my chance now.  Perhaps more important, I practically kill my checker by going the two point.  Meanwhile, my position is stripped out.  Unless I roll cute I will be tiptpoeing all the way home hoping not to get hit - and the race is also close.  I don't think I am up enough for the bring it home safely approach.  I should stuff the bar point now with 13/7 and place immediate pressure on Karen to roll something good - especially while I have the stronger board and the prospect of return shots on most of Karen's hitters.

Note that even in the modified position where Karen has the 4 point covered - a 5 prime waiting to bury me should she hit - it is still only a small error to slot!!  My structure is so weak that it seems I should be going for it now.

**********
Later in the same game.  I doubled earlier.  How to play 61?

is karendavis

score: 0
pip: 102
7 point match
pip: 98
score: 0

is Chutzpah
XGID=aBBBBB------BAA-bAacdbb---:1:-1:1:61:0:0:0:7:10
to play 61

1.XG Roller++17/10eq: +0.637
Player:
Opponent:
81.89% (G:7.94% B:0.06%)
18.11% (G:3.65% B:0.13%)
2.XG Roller++17/11 13/12eq: +0.617 (-0.019)
Player:
Opponent:
81.06% (G:7.43% B:0.06%)
18.94% (G:2.83% B:0.06%)
3.XG Roller++17/11 12/11eq: +0.613 (-0.024)
Player:
Opponent:
80.96% (G:7.03% B:0.05%)
19.04% (G:2.97% B:0.12%)
4.XG Roller++17/11 14/13eq: +0.595 (-0.042)
Player:
Opponent:
80.17% (G:7.33% B:0.06%)
19.83% (G:3.36% B:0.07%)
eXtreme Gammon Version: 2.02, MET: Kazaross XG2
I don't understand this one.

The best I can come up with is that my play (17/11, 14/13) leaves only two hitters, as does the best play (17/10) ... but ...

The better play gives double 4's as an extra cover number for the six point next time.  Also, if I am hit, I get a couple more return shots from the bar, plus I am better diversified to make another point somewhere should Karen dance again next time or to hit should she come in with a single six.
************
I trail 6 away 5 away and have 33 to play.  Your move?

is karendavis

score: 2
pip: 143
7 point match
pip: 156
score: 1

is Chutzpah
XGID=----bBD-C-A-bCa--d-d-b--AA:0:0:1:33:1:2:0:7:10
to play 33

1.XG Roller++Bar/22 13/10 6/3(2)eq: -0.013
Player:
Opponent:
50.02% (G:9.20% B:0.34%)
49.98% (G:15.50% B:0.42%)
2.XG Roller++Bar/22 13/7 10/7eq: -0.135 (-0.122)
Player:
Opponent:
46.52% (G:8.37% B:0.31%)
53.48% (G:15.31% B:0.41%)
3.XG Roller++Bar/22 13/10 8/5 6/3eq: -0.158 (-0.146)
Player:
Opponent:
46.27% (G:9.78% B:0.38%)
53.73% (G:18.68% B:0.64%)
eXtreme Gammon Version: 2.02, MET: Kazaross XG2
I got this one right but wasn't so sure during the game.  Let's take a guess as to why the right play is right,
Bar/22, 13/10, 6/3(2) blocks his advanced anchor from 6 away.  Since I am down in the race this seems to be the most important factor. 

Making the bar point with Bar/22, 13/7, 10/7 forms four in a row but is a less effective block. 

Making the three point is an added bonus, as my men on the six point have no useful function other than to make a point.  Any hit will be more impactful now.
So, just as the first problem was simple ("up in the race, race") so does this problem seem to be easy ("behind in the race, block").

**********
Later in the same game.  I trail 6 away 5 away and am on roll.  Cube action?
is karendavis

score: 2
pip: 149
7 point match
pip: 133
score: 1

is Chutzpah
XGID=-a-BbBB-C-B-aC---cbd-bA---:0:0:1:00:1:2:0:7:10
on roll, cube action?

Analyzed in XG Roller++ No double Double/Take
  Player Winning Chances: 67.20% (G:14.16% B:0.56%) 67.36% (G:14.38% B:0.56%)
  Opponent Winning Chances: 32.80% (G:6.18% B:0.19%) 32.64% (G:6.22% B:0.19%)
  Cubeless Equities +0.441 +0.963
Cubeful Equities
     No double:+0.741 (-0.018)
xg Double/Take:+0.759
     Double/Pass:+1.000 (+0.241)
Best Cube action: Double / Take
eXtreme Gammon Version: 2.02, MET: Kazaross XG2
Up in the race and shooting at a blot with aces and 64 I tossed the cube.  This appears to be a borderlin double / take.

Karen is safely anchored and has good offensive structure so the take is super easy. 
Part of the double appears to be the score.  Being slightly behind appears to bump the cube decision about .06.  Compared to money, the position is a No Double / Take by .04 while at this score the cube is correct by .02

*************
Later in the same game, and Karen has turned this game around.  Cube action?

is karendavis

score: 2
pip: 130
7 point match
pip: 126
score: 1

is Chutzpah
XGID=-a-BbCC-B-B--B---abcbbb--A:1:-1:-1:00:1:2:0:7:10
on roll, cube action?

Analyzed in XG Roller+ No redouble Redouble/Take
  Player Winning Chances: 61.75% (G:25.08% B:0.70%) 61.90% (G:25.46% B:0.85%)
  Opponent Winning Chances: 38.25% (G:9.52% B:0.49%) 38.10% (G:10.09% B:0.55%)
  Cubeless Equities +0.428 +0.574
Cubeful Equities
     No redouble:+0.538
     Redouble/Take:+0.238 (-0.299)
     Redouble/Pass:+1.000 (+0.462)
Best Cube action: No redouble / Take
Percentage of wrong pass needed to make the double decision right: 28.2%
eXtreme Gammon Version: 2.02, MET: Kazaross XG2
Karen redoubled and I took. The position is a big no redouble for money so the cube is obviously very bad at this socre. She is devaluing her gammons while giving me enormous cube leverage with a possible cube turn to 8 looming on the horizon. As scary as her 5 1/2 prime is, Karen has a lot of work to do. She still has 3 men back held by me broken 4-prime. This offensive structure is dangerous and should be respected.

**********
Very next turn. Karen rolled a god-awful double 4's. I am on roll holding 4 cube. Cube action?

is karendavis

score: 2
pip: 114
7 point match
pip: 126
score: 1

is Chutzpah
XGID=-a-BbCC-B-B--B-----bbcda-A:2:1:1:00:1:2:0:7:10
on roll, cube action?

Analyzed in 4-ply No redouble Redouble/Take
  Player Winning Chances: 59.69% (G:14.21% B:0.62%) 59.67% (G:14.39% B:0.64%)
  Opponent Winning Chances: 40.31% (G:13.62% B:0.21%) 40.33% (G:13.67% B:0.21%)
  Cubeless Equities +0.261 +0.534
Cubeful Equities
     No redouble:+0.525 (-0.010)
xg Redouble/Take:+0.534
     Redouble/Pass:+1.000 (+0.466)
Best Cube action: Redouble / Take
eXtreme Gammon Version: 2.02, MET: Kazaross XG2
I doubled and Karen took.

Once again I am at the very front edge of a borderline Double / Take.

Karen can either drop when she trails 2 away 5 away or take and play for the match.  I "remember" 2a 5a as 25% but it is actually 26%.  So while my redouble is correct it may be more practical to wait.  Karen is obviously better than 25% to win so what I am really threatening?  A duece is obviously very good but even if I hit the game may not be over.  It appears I may be better to wait and see if she cracks some more.  Then my cube would be more difficult to evaluate (from her perspective).

***********
Later in the same game.  Cube is on 8 so it is effectively DMP now.  How to play 11 from the air?

is karendavis

score: 2
pip: 101
7 point match
pip: 131
score: 1

is Chutzpah
XGID=--ABbBB-BaB--BA----bbbbcaA:3:-1:1:11:1:2:0:7:10
to play 11

1.XG Roller++Bar/24* 10/9* 3/2(2)eq: +0.214
Player:
Opponent:
60.68% (G:16.44% B:0.58%)
39.32% (G:15.05% B:0.92%)
2.XG Roller++Bar/24* 10/9*(2) 3/2eq: +0.202 (-0.012)
Player:
Opponent:
60.09% (G:17.64% B:0.73%)
39.91% (G:17.31% B:0.79%)
3.XG Roller++Bar/24* 14/13 10/9*(2) eq: +0.168 (-0.045)
Player:
Opponent:
58.42% (G:16.67% B:0.67%)
41.58% (G:17.82% B:0.57%)
4.XG Roller++Bar/24* 10/9*(2) 2/1eq: +0.155 (-0.059)
Player:
Opponent:
57.73% (G:15.83% B:0.58%)
42.27% (G:19.06% B:0.87%)
5.XG Roller++Bar/24* 13/12 10/9*(2) eq: +0.115 (-0.098)
Player:
Opponent:
55.76% (G:16.22% B:0.65%)
44.24% (G:23.09% B:2.97%)
6.3-plyBar/24* 10/9* 9/7eq: +0.094 (-0.119)
Player:
Opponent:
54.72% (G:14.99% B:0.43%)
45.28% (G:25.42% B:3.58%)
eXtreme Gammon Version: 2.02, MET: Kazaross XG2
Best is the sickly looking Bar/24*, 10/9*, 3/2(2).  Her 5 prime is still strong as acid, so I really don't want to get hit here.  My goal should be to simply come home safe and win the race. 

I played the more "natural" or at least not ugly looking Bar/24*, 13/12, 10/9*(2).

Scratch the DMP comment.  The computer play is also best for money.  I guess the key to the position is that 5 prime / 5 point board.  I really don't want another checker sent back under any circumstances and that appears to be the most important factor.

July 1, 2012

Moonshadow race recube

Here is some EPC practice.  For money and also ATS.

Attempting to use 'Stick's EPC methodology.' See my earlier post http://bigmoneybill.blogspot.com/2011/12/racingepc-and-prop-57-practice.html for more detail.

****************
First, for money. I would be on roll holding a 4 cube.  Cube action?

is Moonshadow

score: 0
pip: 73
Unlimited Game
Jacoby Beaver
pip: 55
score: 0

is Chutzpah
XGID=-EBDB-----A-----A--feba-a-:2:1:1:00:0:0:3:0:10
on roll, cube action?

Analyzed in XG Roller++ No redouble Redouble/Take
  Player Winning Chances: 75.28% (G:0.00% B:0.00%) 75.33% (G:0.00% B:0.00%)
  Opponent Winning Chances: 24.72% (G:0.00% B:0.00%) 24.67% (G:0.00% B:0.00%)
  Cubeless Equities +0.506 +1.013
Cubeful Equities
No redouble:+0.800 (-0.050)
Redouble/Take:+0.850
Redouble/Pass:+1.000 (+0.150)
Best Cube action: Redouble / Take
eXtreme Gammon Version: 2.02

Moonshadow's EPC isn't too difficult.  73 Raw + 7 for a nice position or about 80 pips.

Mine (chutzpah) is more difficult. 
Trice's stack and straggler would indicate ... 15 x (3.5) + stragglers minus 4 ...
or, 52.5 + 26 - 4 = 74.4 pips

cube action:  74.4 divide by 7 is about 10.5 less 3 or 7.5 pips.
so last take is 74.4 + 7.5 or 82 pips.
Double if moonshadow is 80 pips or more
Redouble if moonshadow if is 81 pips or more.

So by my interpreation of Trice's rules  this would be No Redouble / Take.

Yet XG clearly shows this is a cube.  Not sure if I made a mistake above or perhaps the formula is not totally reliable for a position such as this.

**************
Same position from the actual match.  I trail 7 away 6 away and am holding a 4 cube.  Cube action?

is moonshadow

score: 1
pip: 73
7 point match
pip: 55
score: 0

is Chutzpah
XGID=-EBDB-----A-----A--feba-a-:2:1:1:00:0:1:0:7:10
on roll, cube action?

Analyzed in XG Roller++ No redouble Redouble/Take
  Player Winning Chances: 75.26% (G:0.00% B:0.00%) 75.33% (G:0.00% B:0.00%)
  Opponent Winning Chances: 24.74% (G:0.00% B:0.00%) 24.67% (G:0.00% B:0.00%)
  Cubeless Equities +0.505 +1.152
Cubeful Equities
     No redouble:+0.903 (-0.097)
     Redouble/Take:+1.152 (+0.152)
xg Redouble/Pass:+1.000
Best Cube action: Redouble / Pass
eXtreme Gammon Version: 2.02, MET: Kazaross XG2

I think most of the above calculations aplly to this position as well.  ie, what is the money cube action?  What adjustments do we need to make for the particular match score?

So for more money I am thinking No redouble / Take but the match score might be different.

If I recubed, Moonshadow could either drop or take for the match.  Dropping he would be down 6 away 3 away or 29%.  So his takepoint is 29%, or considerably higher than money.

So, from my point of view, it is clearly a recube.  And I wouldn't know about the take or not, but that's his problem.

It turns out the position is a large pass.  XG implies moonshadow wins about 25% - enough for money but short of the 29% needed at this score.