Brays Learning Curve: Count the Ways

 

Money Play. Should Red double? If doubled, should White take?

2018 - Beginners 10

XGID=–DF-aCB———–bdbbbb-:0:0:1:00:0:0:3:0:10

This type of position is fairly common so it is best to know how to deal with it.

First, it should be clear that Red should double. With a 15-pip lead in the race and multiple market-losing sequences not doubling here would be a double blunder.

The interesting question is whether or not can White can take. His thinking should go along these lines:

Red will leave me a shot with 62, 26, 44, 55 and 66. I will hit that 30% of the time so that is 1.5 wins out of 36.

What about the race? Red is nominally 15 pips ahead but that is not a true count. He has six checkers on his 3-pt and four checkers on his 2-pt. that will add approximately 6 pips to his adjusted pip count. In addition, he will have empty 4- and 5-pts in the bear-off so that will create further inefficiencies for him. On the down side he has only two crossovers and two pips to get his checkers home while I have 4 crossovers and 15 pips to roll before I can begin to bear-off.

In the 31 games where he doesn’t leave me a shot, can I win 7.5 of them to bring me up to the nine games I need to win to accept the double? To answer that question requires both experience and judgment but it can be made a lot easier if you have a reference document. Luckily, you will find “Backgammon Races” in the download section of my website: www.chrisbraybackgammon.com

The answer in this particular case is that White can take with relative comfort. The key to learning is then to adjust the position to find out what happens when things change. Move the spare on White’s 4-pt to his 5-pt and he can still take the double but move it to his 6-pt and the position becomes a drop.

In the initial position if we move one of the spare checkers on Red’s 3-pt to his 6-pt the position becomes double/drop because 44,55 and 66 now play safely. So small differences in the position can make a big difference to the cube action – tricky game backgammon.

 

Rollout Data from Extreme Gammon

Beginners 10 Rollout

Bray’s Learning Curve — A Great Member Benefit
Bray’s Learning Curve is a USBGF online series by author Chris Bray. Each week Chris lends his sharp insight and easy to understand analysis to help you improve your game. Visit the USBGF Facebook page every Monday to view an interesting backgammon position and join in the lively discussion, return on Tuesday to view the answer. In addition, as a USBGF member, you get access to this companion blog article that includes an expanded explanation.  More about Chris Bray

 

Brays Learning Curve: Match Play Problem

Match Play. Score 4-4 to 7. Should Red redouble? If redoubled, should White take?

 

2018 - Experts 9

XGID=—B-aDBBB—B–aAbbbc-bb-:0:0:1:63:4:6:1:7:10

Once again, the match score dominates the doubling decision.

For money this would be a very premature redouble as White has all his checkers in play and,  owning the cube, he would be in a powerful position to redouble Red if the game turned around.

However, at this match score the cube is valueless to White and so it is merely a question of whether Red is a sufficient enough favourite to redouble now.

White’s point of last take is 25% (the match-winning chances he would have if he dropped the redouble). Is Red close enough to 75% winning chances to redouble? As ever that is a matter of using experience to make the judgement and an exact percentage estimate is impossible.

However, Red has a five-point prime, a five-point home board and White is on the bar. He is certainly a strong favourite. Over the board I redoubled this position and my opponent dropped.

White should have taken as you can see from the rollout below. Red is near the top of his doubling window but not above it. Therefore, the answer is that Red should redouble and White should take.

Rollout Information from Extreme Gammon

Experts 9 Rollout

Bray’s Learning Curve — A Great Member Benefit
Bray’s Learning Curve is a USBGF online series by author Chris Bray. Each week Chris lends his sharp insight and easy to understand analysis to help you improve your game. Visit the USBGF Facebook page every Monday to view an interesting backgammon position and join in the lively discussion, return on Tuesday to view the answer. In addition, as a USBGF member, you get access to this companion blog article that includes an expanded explanation.  More about Chris Bray

 

Brays Learning Curve: Good Numbers and Bad Numbers

Money Play. How should Red play 43?

2018 - Intermediates 9

XGID=-BbC-BB-D——–bbcd–bB-:0:0:1:43:0:0:3:0:10

This is not a very difficult problem but Red went astray over the board by playing 24/21, 8/4, which is an unnecessary overplay. White replied with 64, played 7/1*, 5/1 and after Red fanned, White won with cube.

Red should observe that White has 13 checkers in the attack zone and that should flag up an immediate warning. Those extra checkers on the 6- and 5-pts are just itching to join the battle. At the moment White’s sixes and some of his fours play badly but not after 24/21, 8/4.

Equally well Red cannot afford the luxury of the ‘safe’ play which puts a third useless checker on his ace-point and does nothing to help his position.

The correct play is 8/5, 8/4 which puts the checkers where Red wants and just as importantly does not allow White an attack. There is also some duplication of twos.

White is a strong favourite irrespective of which play Red chooses but anything other than 8/5, 8/4 is a bad blunder.

They key is that Red must stop all those checkers in White’s home board coming into play.

Rollout Information from Extreme Gammon

Intermediates 9 rollout

 

Bray’s Learning Curve — A Great Member Benefit
Bray’s Learning Curve is a USBGF online series by author Chris Bray. Each week Chris lends his sharp insight and easy to understand analysis to help you improve your game. Visit the USBGF Facebook page every Monday to view an interesting backgammon position and join in the lively discussion, return on Tuesday to view the answer. In addition, as a USBGF member, you get access to this companion blog article that includes an expanded explanation.  More about Chris Bray

 

 

 

 

Brays Learning Curve: Blitz

Money Play. How should Red play 31?

2018 - Beginners 9

XGID=aBBAa-B-BA–cCA–e-e—-A-:1:-1:1:31:0:0:3:0:10

This position is used to highlight a very common error amongst beginners, intermediates and sometimes even experts.

Red has doubled and embarked on a blitz. Sadly, he has thrown a poor number. Many players now think that they must give up on the blitz and tighten things up.

I would expect to see 13/9 played quite often and the even weaker 14/13, 9/6 will have quite a few supporters.

The basic strategy for such positions is to keep blitzing until it is no longer possible. This means that in this position the correct play is 8/4*. There is a huge difference between having two rather than one opposing checker on the bar. One bad roll from White, particularly staying on the bar, could see him quickly lose a gammon.

The game-winning percentage for all three of the plays discussed is very similar but 8/4* wins 10% more gammons and that is the big difference.

8/4* leaves five Red blots and that puts many players off making the correct play. Yes, Red will lose some games, and even gammons, when things go badly, but there are very few certainties in backgammon and Red can only play what the dice give him.

Any play other than 8/4* is bad blunder. So remember, have the courage of your convictions, and blitz aggressively until that plan is no longer viable.

Rollout Data from Extreme Gammon

Beginners 9 Rollout

Bray’s Learning Curve — A Great Member Benefit
Bray’s Learning Curve is a USBGF online series by author Chris Bray. Each week Chris lends his sharp insight and easy to understand analysis to help you improve your game. Visit the USBGF Facebook page every Monday to view an interesting backgammon position and join in the lively discussion, return on Tuesday to view the answer. In addition, as a USBGF member, you get access to this companion blog article that includes an expanded explanation.  More about Chris Bray

 

 

Brays Learning Curve: Complexity

Match Play. Red trails 4-6 to 7 (Crawford). How should Red play 63?

2018 - Experts 8

XGID=—B-aDBBB—B–aAbbbc-bb-:0:0:1:63:4:6:1:7:10

This position was originally posted on Facebook by Phil Simborg. In terms of degree of difficulty this is a very high tariff problem.

If this was a money game with Red holding the cube on 2 then the answer would be the simple 17/8. Every other play loses too many gammons.

However, this is the Crawford Game and Red must win it in order to continue the match. Gammons are irrelevant and so Red just needs to make the play that wins the most often.

I think a lot of players would elect to play 17/14, 13/7, leaving no direct shots but whenever White rolls a 5 or a 6 Red will very likely be in trouble and what does Red plan to do on his next roll even if White rolls small numbers? That is the key to the problem.

The more direct approach is 17/11, 8/5*, employing the standard backgammon theory of attacking a lone blot. Red may be able to execute a blitz or possibly create a prime.

The one move nobody looks at 17/11, 13/10!! A passive move exposing two blots to direct shots!

Whenever White rolls a 5 or a 6 Red will be in big trouble, although he will have a small amount of residual equity. The big gains come on the 16 rolls when White doesn’t roll a 5 or a 6. Now Red is ideally placed to attack/prime White’s rear checker.

The difference between 17/11, 8/5* and 17/11, 13/10 is small but small differences count for a lot in backgammon. Not one in a hundred players would find and, more importantly, play 17/11, 13/10 over the board demonstrating just how difficult the game can be. Even analysing in the calm of one’s study it is hard to find the right play.

The key is that having once seen the solution you can now take this type of thinking and apply it to future problems even though such a problem may not occur again for quite some time.

Rollout Information from Extreme Gammon

Experts 8 Rollout

Bray’s Learning Curve — A Great Member Benefit
Bray’s Learning Curve is a USBGF online series by author Chris Bray. Each week Chris lends his sharp insight and easy to understand analysis to help you improve your game. Visit the USBGF Facebook page every Monday to view an interesting backgammon position and join in the lively discussion, return on Tuesday to view the answer. In addition, as a USBGF member, you get access to this companion blog article that includes an expanded explanation.  More about Chris Bray

Brays Learning Curve: Run or Prime?

Money Play. How should Red play 63?

2018 - Intermediates 8

XGID=-a-BBCCBA———ccbbcBa-:1:1:1:63:0:0:3:0:10

 The age-old question: should you build the full prime with 8/2, 5/2 and perhaps crack it as soon as next turn, or use that precious 6 to run with either 23/14 or 22/17, 8/5?

When I had this position as White, I knew what I wanted my opponent to do and that was to run. He very kindly obliged and after a couple of good rolls I was actually able to play on for, and win, a gammon.

The correct play by quite some way 8/2, 5/2 – see the rollout below. The keys to the position are:

  • A full prime is much stronger than a five-point prime and even if Red cannot escape a checker next turn, he will still probably have a five-point prime, so he will be no worse off and, if he rolls a six, he is nearly home free.
  • Crucially, White must play before Red rolls again and facing a full prime he will have to move on his side of the board. Big numbers like 64, 65, 55, 54 etc now severely damage his position, giving Red gammon opportunities.

My rule of thumb in such positions is to take the full prime if it is on offer and that rule has stood me in good stead throughout my playing career. If Red had a 65 to play then 23/27, 8/3 would be correct.

Note that 23/17, 8/5 is much better than 23/14 because it halves the gammon losses. The former is an error, the latter is a blunder. Players often forget to take gammons into account properly when deciding upon a move. 23/14 exposes three blots and that is too many when there is a sensible alternative.

So, remember, hardly ever turn down a full prime!

Rollout Information from Extreme Gammon

Intermediates 8 rollout

Bray’s Learning Curve — A Great Member Benefit
Bray’s Learning Curve is a USBGF online series by author Chris Bray. Each week Chris lends his sharp insight and easy to understand analysis to help you improve your game. Visit the USBGF Facebook page every Monday to view an interesting backgammon position and join in the lively discussion, return on Tuesday to view the answer. In addition, as a USBGF member, you get access to this companion blog article that includes an expanded explanation.  More about Chris Bray

 

 

Brays Learning Curve: Hit or Point?

Money Play. How should Red play 42?

2018 - Beginners 8

XGID=aa—BD-C—eDa–c-dA—A-:1:-1:1:42:0:0:3:0:10

This is a type of position that I constantly see misplayed by beginners and intermediates.

They nearly always play 20/14*, putting a second checker on the bar. Hopefully not many players would select the craven 24/20, 13/11! Such a passive move is not the way to winning backgammon.

As the great Paul Magriel used to say, “put ‘em where you want ‘em”. This should give you a clue!

The correct play is 8/4, 6/4. This gives Red an excellent long-term asset and considerably reduces White’s chances of counter-play. A quarter of the time he will still be shooting at the White blot on Red’s 14-pt next turn.

8/4, 6/4 wins more games and more gammons than 20/14*. That may surprise many, but that extra home-board point, which is also part of a potential prime, really stifles White’s play.

If you don’t believe this try playing the position a few times. You will soon see that making the 4-pt is much stronger than hitting the extra blot.

Rollout Data from Extreme Gammon

Beginners 8 Rollout

 

Bray’s Learning Curve — A Great Member Benefit
Bray’s Learning Curve is a USBGF online series by author Chris Bray. Each week Chris lends his sharp insight and easy to understand analysis to help you improve your game. Visit the USBGF Facebook page every Monday to view an interesting backgammon position and join in the lively discussion, return on Tuesday to view the answer. In addition, as a USBGF member, you get access to this companion blog article that includes an expanded explanation.  More about Chris Bray

 

 

Simborg Video Lesson: The Rule of Four

Simborg Video Lesson: The Rule of Four.
Featured content exclusively for USBGF Premium, Youth, & Basic Members.

[Read more…]

USBGF Quizzes 2010 – 2012

California State Quiz – Los Angeles, California, December 2012

Ernest Ho, winner
Ernest Ho, winner

 

Cheryl Andersen
Cheryl Andersen, winner
 

Giants World Challenge Quiz – Pittsburgh, Pennsylvania: February 2012

 

 

 

Falafel Natanzon, Open Division
 

Andrew Liebenthal, Advanced Division

 

USBGF Illinois State QuizPeoria, Illinois; October 16, 2011

Mary Hickey, Open Division winner

Ben Friesen

 

 

Ben Friesen,

Advanced Division winner

 

 

 

 

 

 

 

 

 

USBGF World Giants Quiz Winners

Giants Winner Falafel Natanzon and Open Winner Ed Rosenblum with USBGF President Perry Gartner and USBGF Board Member Lynn Ehrlich. Advanced Winner Irving Gold not present

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

USBGF Last One Standing Quiz – Novi, Michigan – July 2011

Mary Hickey, Open Division winner
 

 

USBGF Chicago Open Quiz by Mochy – Chicago, IL, May 30, 2011

Open Division–Petko Kostadinov, Falafel Natazon, Kit Woolsey (tied); Advanced Division–Lucas Bauer
 

 

 

 

 

 

 

 

 

 

 

 

 

 

USBGF Ohio State Quiz — Last Man Standing Cleveland, OH, March 2011

Open DivisionMary Hickey, 1st

Mary Hickey

Mary Hickey

Advanced Division — Ben Friesen, 1st
 

 

USBGF Al Tesoro Memorial Quiz and Lecture — Fort Lauderdale, FL; August 2010

Ray Fogerlund

 

Open Division — Ray Fogerlund, 1st

 
 

 

Advanced Division— Efim Liberman, 1st

 

 

 

USBGF Howard Ring Memorial Quiz — Van Nuys, CA., June 2010

Alex Eshaghian and John O’Hagan

Open Division — John O’Hagan, 1st; Richard Munitz, 2nd
Advanced Division — Alex Eshaghian, 1st; Cheryl Andersen, 2nd

MathFest 2011 Backgammon Quiz

In August 2011, over 1000 mathematicians gathered in Lexington, Kentucky for MathFest 2011,  the annual summer meeting of the Mathematical Association of America. MathFest 2011 featured “Backgammon Night,” a free social event offering backgammon group lessons, a backgammon quiz designed especially for top-level mathematicians, and a backgammon tournament to test their newly-acquired skills.

The quiz, which we are presenting here, poses ten problems, with some weighted more highly than others, so that a perfect score nets 13 points. Art Benjamin, math professor at the Harvey Mudd College in Claremont, California, and a member of the USBGF Board of Directors, constructed the quiz. Art, along with Jennifer Quinn, math professor at the University of Washington, Tacoma, gave a post-quiz lecture, explaining the answers.

You can see the quiz, with answers, by downloading the PDF version (about 627 kB):  MathFest 2011 Backgammon Quiz.

USBGF Ohio State Quiz

By John O’Hagan and Phil Simborg


You can view the problems and answers below, and see how well you do.

The Problems:



Chuck Bower’s Monte Carlo Quiz, Part 2

Chuck Bower

Play Along at Monte Carlo, Part 2

By Chuck Bower


This is the second and final piece of a two part Magriel-Gartner Quiz. Part 1, with an introduction is found here.

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Chuck Bower’s Monte Carlo Quiz, Part 1

Chuck Bower

Play Along at Monte Carlo, Part 1

By Chuck Bower


   

Introduction


The move-by-move type of quiz I am presenting here was invented by the great theoretician and teacher Paul Magriel. It is also a favorite of USBGF chairman and master instructor Perry Gartner, who long ago recognized its value as a learning tool. To use it most efficiently, please follow these guidelines:   1) Work through the entire quiz, making all of your play or cube choices before looking at the scoring and commentary section.
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Al Tesoro Memorial Quiz

USBGF Al Tesoro Memorial Quiz and Lecture

By Karen Davis and Rochelle Hasson    

Al Tesoro, a beloved member of the Florida backgammon community for almost three decades, was no intellectual lightweight. Born in Rome, Italy, he moved with his successful business-oriented family to New York at age 4. He returned to Europe for his education, acquiring a bachelor’s degree in Geneva, and then came back to the USA to complete the process, getting his Masters and Ph.D. in physics from Columbia. His 1967 doctoral dissertation was entitled “On the Production of Neutrino Pairs by the Annihilation of Two Photons.”    

After teaching for a few years, Al focused his intense intellectual curiosity upon games. He loved everything from cards at the Mayfair to chouettes in New York and Fort Lauderdale bars to pick-up chess games on the sidewalks or in the parks of Manhattan. His best backgammon event was the doubles, where he teamed up with Dr. Bob Hill, coming in first or second in 2001 (Florida State); 2002 (Mid-West Championships), and 2004 (Florida), and taking fourth place in the Michigan Open in 2003. But Al would always be a “pre-bot” player. He had worked hard to learn the game before software existed to point out the “right” play, and continued, to his dying day, to study the game “au natural.”