Positions From Peoria

by Gerry TanseyIMG_4632

The Illinois State Backgammon Championships were held on the weekend of October 10-12 in Peoria.  Tak Morioka, the prolific craftsman of backgammon boards and beloved ambassador of the game, won the Open Division.

Tak Morioka

Tak Morioka

Petko Kostadinov, the #6 Giant of Backgammon, defeated St. Louis’ own David Todd to take down the Masters event.  Linda Rockwell, Sue Will, and Butch and Mary Ann Meese, once again put on a fantastic show for the backgammon players.

Petko Kostadinov

Petko Kostadinov

Here are a couple of positions that came up over the weekend.

 

 

 

 

 

Peoria 1

 

First of all, if you are thinking, “I would have doubled,” you are right.  White should have doubled before this roll, and it is a whopper-sized error to fail to do so.  Even though White is down 7 pips in the race, there are enough market-losing sequences to merit a cube turn.  White could roll something that double-hits or makes the bar point.  Sometimes White hits one checker and Black fans or enters poorly.  Meanwhile, White doesn’t have any rolls that are truly horrible.  White must double in order to take advantage of the crushing sequences leading to gammons.  Black has a big take, as none of his checkers are out of play, the race is close, and there is plenty of game left.

As it stands, White did not double and he rolled 32.  All other things being equal, White should prefer to hit the checker on the 21 point to the checker on the bar point, as this play gains more ground in the race.  In fact, this is what White did.  However, all other things are not equal in this position.  If White hits the 21-point checker, Black can make White’s bar point with any 7, plus 62 and 63, for a total of 10 numbers, after which White’s advantage evaporates.  A much better play is to disrupt Black’s bid for an advanced anchor with 10/7*/5.  After this play, it is hard to find many rolls for Black that will leave him feeling good about his game.  Even plays that leave the bar point slotted are better than hitting on the 21 point.

Peoria 1

 

1. Rollout1 10/7* 7/5 eq: +0.756
Player:
Opponent:
65.52% (G:28.29% B:1.70%)
34.48% (G:10.05% B:0.50%)
2. Rollout1 13/11 10/7* eq: +0.707 (-0.049)
Player:
Opponent:
65.86% (G:26.64% B:1.61%)
34.14% (G:10.87% B:0.75%)
3. Rollout1 24/22 10/7* eq: +0.705 (-0.051)
Player:
Opponent:
65.57% (G:27.40% B:1.84%)
34.43% (G:10.95% B:0.54%)
4. Rollout1 24/21* 10/8 eq: +0.667 (-0.089)
Player:
Opponent:
64.13% (G:24.67% B:1.61%)
35.87% (G:8.78% B:0.39%)

In this next position, White is a Giant of Backgammon, facing a 42 from the bar.

Peoria 2

Earlier, White had gotten Black to take a horrible gammonish cube, and the attack was going swimmingly until now.  After entering with the 2, White moved the only available 4 that didn’t leave a shot, 8/4.  I think most players would have done this.  The trouble is that this position requires much more urgency on White’s part!  Black can roll any 2, 4 or 8 to complete a 5-point prime, and White’s back checker will not be at the edge of that prime.  If Black makes the 5-point, White will be on the underdog side of a prime-versus-prime battle, and suddenly White’s big racing lead is no longer the asset it once was.

That’s right folks.  It’s time for a banana split play!  White should play Bar/23, 5/1*, leaving two blots in his board, but maintaining a 4-to-2 advantage in home board points.  Black’s threat is severe enough that this drastic action is required.  Black dances on 16 rolls, after which White may be able to hit Black’s 20-point blot or re-create a 5-point board.  Even if Black enters, White may have a shot at Black from the roof.  The fight is for Black’s 5 point.  If Black wins that fight, he usually wins the game.  White cannot cede that point for free.  The quiet play is a whopper-and-a-half sized error.

Peoria 2

1. Rollout1 Bar/23 5/1* eq: +0.005
Player:
Opponent:
49.15% (G:33.25% B:0.84%)
50.85% (G:14.35% B:0.86%)
2. Rollout1 Bar/23 8/4 eq: -0.157 (-0.162)
Player:
Opponent:
45.18% (G:25.97% B:0.56%)
54.82% (G:9.50% B:0.45%)

5-Point or 4-Point?

IMG_4632by Gerry Tansey

Prior to reaching the position below, both players had played a 52 by splitting the back checkers and bringing down a man from the midpoint.  How should White play a roll of 31?  What about a roll of 42?

 

5-2

In each case, White must decide whether to make an offensive point or a defensive anchor.  Good arguments can be made for each play.  If White makes an offensive point, White unstacks her heavy 8- and 6-points, starts to build her board, and puts pressure on Black’s back checkers.  If White makes a defensive anchor, she shuts down Black’s ability to score a quick knockout offensively, and the security of the advanced anchor allows White to play more freely up front.

Let’s see what XG thinks:

3-1

1. Rollout1 8/5 6/5 eq: +0.238
Player:
Opponent:
55.71% (G:15.57% B:0.57%)
44.29% (G:11.03% B:0.41%)
2. Rollout1 24/21 22/21 eq: +0.092 (-0.146)
Player:
Opponent:
51.72% (G:12.01% B:0.44%)
48.28% (G:9.02% B:0.32%)

 

 

4-2

1. Rollout1 24/20 22/20 eq: +0.200
Player:
Opponent:
54.55% (G:10.74% B:0.30%)
45.45% (G:7.09% B:0.25%)
2. Rollout1 8/4 6/4 eq: +0.167 (-0.033)
Player:
Opponent:
54.18% (G:15.08% B:0.58%)
45.82% (G:11.53% B:0.45%)

In each case, XG says, “Make the 5-point!”  If White rolls 31, she should make her own 5-point, and it is a big blunder to do anything else.  If she rolls 42, she should make Black’s 5-point (her own 20-point), although the plays are much closer in this case.  The reason for the size difference between the errors has to do with the heavily stacked 8- and 6-points.  If White makes her 4-point with 42, at least she is unstacking the heavy points.  By contrast, if she makes the anchor with 31, she is both making an inferior point and refusing to unstack the big towers, so this should be a much bigger error.

These two positions illustrate a principle articulated by Nack Ballard: “Either 5-point is better than either 4-point.”

There is one wrinkle I’d like to point out, however.  Both of these rollouts are money game rollouts.  In match play, if White is at a score in which a gammon is useful to her but not to her opponent (2-away / 1-away Crawford, for example), she should make her offensive 4-point with the 42.  In doing this, she gives up very few wins in exchange for a much more gammonish position.

Here’s a position that arose in the chouette the other night.  The rollout results immediately follow, so scroll slowly if you don’t want to see them right away.

chouette

 

1. Rollout1 24/20 22/20 eq: +0.203
Player:
Opponent:
53.73% (G:15.19% B:0.59%)
46.27% (G:7.93% B:0.31%)
2. Rollout1 8/4 6/4 eq: +0.135 (-0.068)
Player:
Opponent:
52.21% (G:18.40% B:1.41%)
47.79% (G:12.87% B:0.67%)

White failed to cover the blot on his 5-point, but he did roll a pretty good 42 nonetheless.  Even though making the offensive 4-point unstacks two heavy points, it is right to make the 20-point anchor in this position, and by an even larger margin than it was with the 42 earlier.  Here, Black already has a two-point board, so if White makes his own 4-point, he is only drawing even in development with Black while leaving a blot in his board and split back checkers.  By making the 20-point, White shuts down Black’s ability to create quick offense.  Even if Black is able to hit White’s 5-point blot, it is not even close to enough to decide the game.  And of course, “either 5-point is better than either 4-point.”

This next position was posted recently at the bgonline forum by Backgammon Giant John O’Hagan:

4-3

1. Rollout1 Bar/21 8/5 eq: -0.179
Player:
Opponent:
45.99% (G:13.38% B:0.61%)
54.01% (G:16.88% B:1.17%)
2. Rollout1 Bar/21 24/21 eq: -0.200 (-0.021)
Player:
Opponent:
45.25% (G:11.56% B:0.44%)
54.75% (G:14.91% B:0.66%)
3. Rollout1 Bar/22 13/9* eq: -0.212 (-0.033)
Player:
Opponent:
46.52% (G:12.83% B:0.72%)
53.48% (G:20.40% B:2.10%)

I must confess that I would have quickly made the advanced anchor by playing Bar/21 24/21.  Although making the 5-point with the 3 has some appeal, I would have been too afraid of Black’s four builders aiming at my 21-point blot to make that play.  And yet, XG has a small but clear preference for making the 5-point.  Black does not always point on White’s head next turn, and with the 5-point made, it is not always the end of the world when it happens.  Sometimes Black rolls a number like 41, which Black should use to make his 5-point.  But if he does this, he leaves White many shots to hit back.  Further, if White makes the anchor rather than his own 5-point, he leaves Black with a direct shot to send a fourth checker back.  While it is not a disaster if this checker is hit, it does mean that White will have difficulty winning the game going forward.  It is too early for White to give up going forward when he has the option of taking the lead in home board points by making his own 5-point.  While making the 5-point leads to more gammon wins for both sides, these extra gammons roughly cancel out, and making the 5-point simply wins more games.  Yet again, we have confirmation that “either 5-point is better than either 4-point.”

To me, the craziest thing about this position is the fact that the third-best play, Bar/22 13/9*, is not that far behind.  In fact, it seems to be the play that wins the most games.  It loses too many gammons to be the right play for money, but it is almost certainly right at DMP.  And there is no way I would have even considered it over the board.  Here we see the power of yet another backgammon adage: “When in doubt, hit.”

 

A Sly Look at Tino vs. Senkiewicz

by Sly Sylvester (Courtesy of the Flint Area Backgammon News, January, 1993)IMG_4598[1]

Senk1

11 Point Match

Score tied at 7-7

Red doubles, should Black take?

A deceptive position indeed!  (At least for me!)

When I first viewed this position, I thought Black had a trivial take.  After further analysis, however, I’m not so sure.  Read on…

When faced with match cube decisions, the first thing that needs to be determined is Black’s Take Point.

At 7-7 in a match to 11:

Score Match Equity
Black Passes (7-8) 41%
Black Takes & Wins (9-7) 67%
Black Takes & Loses (7-9) 33%
67% – 41% = 26% Reward
41% – 33% = 8% Risk

This 26-8 ratio represents approximately a 23% Take Point,  (Take Points are determined by dividing Risk + Reward into Risk.)

Risk = Take 8 = .235
Risk + Reward Point 8 + 26

“So what’s the problem here?” I asked.  Black is slightly ahead in the race 80-83.  And there is still contact.  Surely the contact must help the one owning the cube, right?

Wrong!  Not only does contact not favor Black at all in this position, but the mere prospect of contact greatly inhibits an already poor race.  The two long crossovers that Black is down, plus his poor distribution in his inner board, translate his original 3-pip lead into a racing nightmare.

In my original tinkering with the position, I tried clearing Red’s back checker as soon as possible.  But just relying on Black’s poor distribution is clearly wrong, as I found Black was winning over 30% of the games.

However, when I left Red’s rear checker alone and built his inner board as quickly as possible, contact started paying dividends.  Numbers such as 6-2 should be played 9/1 by Red; 6-3 : 9/3, 5/2; 6-4 : 9/3, 5/1.  As for 6-5, frankly, I’m not sure: 17/6 or 9/4, 9/3?

To help find a solution to this problem, Butch Meese was enlisted to play out the position on the IBM version of Expert Backgammon™.  12,924 rollouts yielded:

Red wins 8,995 single games = 69.6%
Red wins 595 gammons = 4.6%
Black wins 3,434 single games = 26.8%

If we multiply these figures out from Black’s point of view, we find the following:

Black Loses: 69.6% x 33% Match Equity = 23.2%
4.6% x 0% Match Equity = 0%
26.8% x 67% Match Equity = 17.8%
+41.0%

It would appear from these results that taking the cube yields 41% Match Equity and that passing yields 41% Match Equity!  Close decision, eh?!

Still, there are some factors that favor Black.  First of all, the computer rollouts are cubeless – clearly a disadvantage for Black who has a redouble point of 50%+,  Also, Red should pass a redouble at <33%, so any positions where Black goes from <50% to >67% should be counted as Black wins, whereas the computer continues to roll them out, giving Red some wins he doesn’t deserve.

Furthermore, Red may not play the position to his greatest advantage, as I alluded to above.  This is not something you can count on, but carefully factor it into your judgment of the position.

In summary, this position is clearly a strong double and not-so-clearly a close take.

 

Note:  This decision was correct in 1993 and is still correct today.  Here is the eXtreme Gammon analysis:

Senk

There are a couple of notes on the checker plays mentioned in the article.  The 6-2 played 9/3, 5/2 is correct according to eXteme Gammon.  For the 6-3 the computer prefers 9/6, 9/3 by a small margin.  The computer plays the 6-4 16/6.  According to the computer, the answer to Sly’s question on how to play the 6-5 (either 17/6 or 9/4, 9/3) is 9/4, 9/3.

 

Dice Abandonment Disorder (DAD)

Or

How Anthropomorphizing One’s Dice Leads to the Loony Bin

by Jana Bohrer

Anthropomorphization – “To attribute human personality to things not human.”  Webster

Backgammon players are masters of the art of breathing life into inanimate cubes – specifically dice.  Players have been known to name their dice and imbue them with personalities. named dive

Certainly they name the rolls – “The Boys” for 6-6 and “The Girls” for 5-5, etc.

But, some go too far and complete a process of psychological transference.  They become their dice.

The double helix of the DAD sufferer

The double helix of the DAD sufferer

This can have serious repercussions.  The process of transference that allows players to merge with, or “become one” with the dice creates a new, symbiotic entity in the player’s mind.  The dice and the player are now a single brain with a common goal – WINNING!  Or so the player believes.

This is fine when things are going well and the dice are responsive to every command.  They hit, they cover, they prime, they leap and they never, EVER dance.

dancing

 

Studies have shown that at this stage, the player is rarely even aware that he and the dice have merged.  In fact, he attributes all of his wins to skill!  He is totally oblivious to the part the dice are playing in his string of victories!

But what happens when things stop going so well?

What happens when the dice turn to  the dark side?

Psychologists have yet to grant the disease a name, so I have taken the liberty of creating one –
Dice Abandonment Disorder (DAD).

The condition is rampant among backgammon players and is also very prevalent within the craps community.  Studies show that 1 in every 2 players is suffering, or has suffered from, DAD.

The exact causation of DAD remains a mystery.  But at least one prominent Austrian researcher has found some correlation between:

“…dice departure and a lack of proper acknowledgement and appreciation by the host entity.”

“…dice departure and a lack of proper acknowledgement and appreciation by the host entity.”

It seems the dice begin to feel taken for granted and thus, move out.

The disease progresses rapidly.

Phase IDenial The player feels the onset of symptoms but continually insists that nothing is wrong.  He frequently gives in to an uncontrollable urge to dance on a 1 or 2-point board.  He is unable to roll 6-6 unless his opponent has rolled an opening 6-1.  His 5-5 may feel blocked.  But at this stage the player refuses to accept that the dice have left him.  He carries on as usual, believing his superior brain will overcome any temporary lack of luck.

Phase IIAnger The player now has full-blown DAD.  Rage ensues as he realizes that the dice have packed their bags and moved out.  He turns on them.  The dice are now the scapegoat for all misfortunes.  1/3 of patients in this Phase commit dice abuse.  The player may throw the dice into a wall or other hard object. In severe cases, paranoia sets in.  The player’s mind turns increasingly to conspiracy theories in which the dice are the enemy and are planning an assassinatioDice mann.  Victims are heard to say, “My dice are killing me.”  (Some sufferers have gone so far as to claim that JFK won big in a floating crap game in Ft. Worth on the evening of November 21, 1963, and that the dice were lying in wait on the grassy knoll to get their revenge.)

Phase IIIBargaining The player now realizes the error of his ways.  If only he had blown on them more, perhaps the dice would not have left.  If he had just taken a minute to cuddle them, and tell them how much they meant to him, maybe they would still be together.  He promises to buy more comfortable dice cups if they will just come home.  He tells them he will move up to a bigger board in a better neighborhood.  All in vain.

Phase IV – Depression  It becomes clear that the dice have chosen another.  His dice are now cozying up to his opponent! Frequently the sufferer says that he will quit backgammon forever and leaves notes to that effect on his score sheets. Though he rarely follows-through with this threat, it should be taken seriously as a cry for help.

Phase V – Acceptance The victim has reached the end of the road.  It’s all over.  He tells friends and colleagues that while he will always love backgammon, he’s ready to start playing other games, perhaps cribbage or dominoes.  Maybe he will be able to play some BG every other weekend, but he no longer expects to score.

DAD is almost always irreversible. In rare cases, with expert tutelage and intensive primal scream therapy, the player recovers his dice.  But, alas, even in those cases where a cure seems within reach, 99.786 % of players experience a relapse after once again taking the dice for granted and the DAD cycle repeats itself.

DAD is the most vicious dice disease, but there are others.  These include, but are not limited to:

Dice Bewilderment Disorder (DBD) – Continually misreading the dice in a manner favorable only to one’s own position.

Dice Compulsion Disorder (DCD) – An obsessive need to count all doubles rolled by anyone in the world at any time to make sure they are fairly distributed.

Dice Deification Disorder (DDD) – Symptoms include praying to dice, and/or setting up a shrine to dice in the dining room after sacrificing a chicken.

shrine

Dice Exhibitionist Disorder (DED) – Compulsion to roll with a tic, jerk or “flair” that opponents find annoying.

And so it goes…

It is clear that the road to the Loony Bin is paved with dice.  If you have seen yourself in this article, remember that the first step to getting well is recognizing that you have a problem.  SEEK TREATMENT NOW!  Operators are standing by.  Call 1-800-BIG-FISH and set yourself free from DAD forever.

(Side effects of treatment may include: the inability to stop screaming primally, gibbering idiocy, inability to assume any position other than fetal, loss of rolling skills and poverty.)

Best-Kept Secrets: A Gift – by Sly Sylvester

Flint Area Backgammon News – December 1994

by Sly Sylvester IMG_4598[1]

1994 World Cup Finals:
Black (Sly) – Red (Horan)
3rd Match to 11, score tied 6-6

Red on roll.  Cube action?

Sly

Perhaps the best lesson to be learned in this position is that it is equally (if not more!) important to analyze the score, as well as the position.

At this score, we are essentially faced with a 5-point match.  Let’s look at the resulting scores from possible cube actions.  I call these SEVs…Subsequent Equity Values:

Cube Action

Score SEV

Double/Drop

7-6 59-41

Double/Win

8-6

67-33

Double/Win Gammon 10-6 Crawford

85-15

Note that Black’s take point (excluding gammons) is right about that of a money game (approximately 24%).

This position would not appear to be very gammonish, but clearly the majority of gammons favor Red.  This is particularly important at the 5-away/5-away score.  Let’s illustrate this by looking at 0-0 in a 6 point match (6-away/6-away) and SEVs:

Cube Action

Score SEV

Double/Drop

6-5 57-43

Double/Win

7-5

67-33

Double/Win Gammon

9-5

78-22

The Double/Drop and Double/Win equities are very similar.  But, notice the premium to winning a gammon – a 7% increase because of getting to Crawford!  This equity situation clearly suggests that doubling aggressively in a favorable gammon ratio is called for at this score.

I consider the take to be trivial here since Black’s checkers are all still active, he has the bar/mid-point holding position as a first line of defense, and then, lastly, the ace-point game if all goes awry.  Red’s checkers are well-positioned, and, as I said, at this score he should double aggressively with gammons on the horizon.  Verdict:  DOUBLE/TAKE.

Let’s digress for a moment, and look at the most important lesson here:  The world-class player reaches the 5-away/5-away score, and prior to ever moving a checker, knows that he should double aggressively in gammonish positions.  He knows this, and he steers his checkers accordingly.  Sometimes it is even right to make a play that yields less winning chances to augment win-gammon chances!

Secondly, for those of you who are new to this concept of “score analysis first/play the game second”, I suggest you tinker around with the SEVs of various scores at home, and try to work out what types of positions are the most advantageous for you at that score, and how to steer effectively to them.  You will find your opening moves and responses set the tone immediately and probably have the greatest impact on the percentage breakdowns of wins/losses and (again, more importantly) the percentage of gammons in a game.  This is why I say the world-class player knows his SEVs prior to move #1 of a given game.  It’s a little late even at move #2 to start thinking about steering to a holding position or a prime versus prime.

Don’t worry too much, though.  I would guess 90% of all players don’t even know about, or how to, “steer” their checkers.  And, 99% don’t even think about what type of position yielded will give them their best results (i.e. Match Equity) prior to moving the first checker.

I hate to give away too many “secrets”, but I feel that with the advent of neural networks to break down (analyze) positions more accurately, it’s time to open a new chapter for many open and strong open players.

Remember To Take The Upside

by Gerry Tansey IMG_4602[1]

I’m a fan of “Jeopardy!”  However, based on some of the wagering I see, I must conclude that some of the contestants don’t want to win the game.  Let me give an example.  Suppose that Alice has $20,000, Bob has $8,000, and Charlie has -$,2000 (and his fourth Bloody Mary).  Bob hits a Daily Double on the final clue of the Double Jeopardy round.  Bob bets $3,000, sealing his doom with less than half of Alice’s total if he is wrong, but only reaching $11,000 if he is right.

The point here is that a $3,000 bet makes no sense.  It’s much better for Bob to bet everything in this situation.  Bob has no chance of winning if he misses the question, no matter what he wagers, but he is in a much stronger betting position in Final Jeopardy with $16,000 than with $11,000.  Bob could win the game without even answering the Final Jeopardy clue correctly if he has $16,000, whereas he must rely on the parlay “Alice answers incorrectly, Bob answers correctly” in order to win with $11,000.

How does all of this apply to backgammon?  Well, if you take a cube that is on the take/pass borderline, you must know when to redouble when things go your way.  If you don’t maximize your upside, then it is very wrong to take the downside risk in the first place.

Here is a trivial example that came up recently.  I was up 3-0 in a match to 7, and I owned the cube as White in the following position.

 

Tansey1

If I redouble here and Black takes, I will win the match if I win this game.  So if Black decides to take, he should redouble immediately.  The downside risk for Black (loss of the match) is the same, but by redoubling to 8 he maximizes his upside when things go well, namely winning the match rather than just taking a 4-3 lead.

But should Black take this recube if it is offered?  Well if Black passes, he will have to win the match from a 5-0 deficit.  A modern match equity table reveals that Black has about a 15.8 percent chance to do this, provided he is an equal player to White.  So Black should take if he thinks he has a greater than 15.8 percent chance to win.

Black should realize that he is quite a bit worse than he would be in a pure 3-roll vs 3-roll position, where he would have slightly greater than 21% winning chances.  All of White’s doubles except 22 work quite nicely.  White’s worst number is 31, which is only really bad if White follows it up with consecutive aces.  Meanwhile Black’s 22 and 11 do not save a roll.  Basically Black will have to roll an unanswered medium-sized set of doubles to win the game.

Tansey1

 

Analyzed in Rollout No redouble Redouble/Take
Player Winning Chances: 84.03% (G:0.00% B:0.00%) 84.03% (G:0.00% B:0.00%)
Opponent Winning Chances: 15.97% (G:0.00% B:0.00%) 15.97% (G:0.00% B:0.00%)
Cubeless Equities +0.681 +1.502
Cubeful Equities
No redouble: +0.834 (-0.151) ±0.000 (+0.834..+0.834)
Redouble/Take: +0.985 ±0.000 (+0.985..+0.985)
Redouble/Pass: +1.000 (+0.015)
Best Cube action: Redouble / Take

This is a huge redouble, and it is a borderline take.  If you struggled with the take/pass decision, congratulations!  You got this problem right.  If Black feels that he is a stronger player than White, he should pass, but it is really impossible for Black to make a mistake with this position…or so I thought.  In real life I redoubled, Black took, I rolled an average number…and Black didn’t redouble!  Black ended up winning this game for 4 points, and then subsequently the match, one… point… at… a… time.

Here is a less trivial example of a failure to maximize the upside of a take.  White is leading 4-2 in a match to 11 and holding a 2-cube.

the one

Don’t be too enthralled by the close raw pip count.  The reason the pip count is close is the burial of a lot of Black’s checkers on low points.  White is on roll and needs three crossovers before he can start bearing off.  Black is on the bar against a 5-point board.  If Black comes in on his first shake, he will then need three more crossovers before he starts bearing off, assuming he avoids getting hit by a White straggler.  But Black usually needs more than one turn to come in, and White will have already started bearing off if Black fans for a while.  It is easy to imagine scenarios in which Black wins this race, but they simply do not occur often enough.  Even though Black is trailing, this is a huge redouble and a whopper-sized pass.

the one

 

Analyzed in Rollout No redouble Redouble/Take
Player Winning Chances: 82.24% (G:1.05% B:0.01%) 82.31% (G:1.05% B:0.02%)
Opponent Winning Chances: 17.76% (G:0.05% B:0.00%) 17.69% (G:0.06% B:0.00%)
Cubeless Equities +0.655 +1.300
Cubeful Equities
No redouble: +0.863 (-0.137) ±0.003 (+0.860..+0.866)
Redouble/Take: +1.118 (+0.118) ±0.006 (+1.113..+1.124)
Redouble/Pass: +1.000
Best Cube action: Redouble / Pass

In the actual match, Black took this redouble.  White entered both of his checkers in two turns, while Black entered with a 65 after fanning on his first turn.  Black’s third roll was 55, and soon a position similar to the following position was reached, with Black on roll.

Now this one

Analyzed in Rollout No redouble Redouble/Take
Player Winning Chances: 61.99% (G:0.00% B:0.00%) 61.98% (G:0.00% B:0.00%)
Opponent Winning Chances: 38.01% (G:0.00% B:0.00%) 38.02% (G:0.00% B:0.00%)
Cubeless Equities +0.240 +0.725
Cubeful Equities
No redouble: +0.603 (-0.123) ±0.002 (+0.601..+0.605)
Redouble/Take: +0.725 ±0.000 (+0.725..+0.725)
Redouble/Pass: +1.000 (+0.275)
Best Cube action: Redouble / Take

For money, a recube would be a double whopper, but Black simply must make White eat an 8-cube at the score.  If Black loses with the cube on 4, he will have to win the match from a 9-away/3-away score, which he only does about 16 percent of the time.  But it is a lot better for Black to win on an 8 cube than on a 4 cube, as his match winning chances will be nearly 91 percent (at 10-4 Crawford) rather than just shy of 63 percent (at 6-4).  Black is in serious danger of losing his market.  If Black rolls an unanswered set, or if White rolls a missing 5, White will have a huge pass of a recube next turn.

In the actual match, Black did not redouble.  White eventually rolled a 5 that missed.  Black still did not redouble.  Black let the position become a 3-roll vs. 3-roll position before recubing, and White quickly passed.  White went on to win the match at DMP.

Remember, Black’s take of White’s 4-cube was bad in the first place.  But XG issued its judgment of that take assuming perfect play by both sides thereafter.  Black’s misunderstanding of the subsequent cube action made that decision even worse in retrospect.  If you’re going to make a bad take, make sure you maximize the upside.