This Too Shall Pass

 

Sometimes the brain and the mouth are in opposition. Four years ago I made it to the final five at the Blackjack Ball, winner to be crowned King of Blackjack. The first challenge was to count down several decks, with two cards removed, and state the count, and what it meant, e.g. “Plus one, with a high card and a zero-value card.” The second part was a formality, in case someone was using a count with different point values than the counts others used. Except I said: “Plus one, with a low card and a zero-value card.”

“Don’t you mean that the other way, a high card and zero-value?” several asked. No, I was sticking to my guns. I knew what I meant, and the fact that what I said didn’t match mattered not to me. (There was quite a bit of Champagne involved.) And so I was not part of the final four.

 

Last week I was commenting, with Joe Urso, on the finals of the Michigan tournament, an eleven-point match between Marty Storer and Nick Murtos. Commenting is harder than it sounds. You have to talk when, quite often, you should be thinking.

The score is tied 4-4 to 11, and Marty redoubled. Nick thought long and hard, while I commented that his cubeless takepoint was about twenty-six percent, and it seemed to me White had “twenty-eight or twenty-nine percent.” Later, I realized I had made two errors, one leading to the other, and White’s chances were less than twenty-seven percent. How much less I didn’t check. But my friend Edward Onny did. As he is likely not the only one looking it up, I thought I would correct the record by writing this.

White’s chances are considerably less than twenty-seven percent, around twenty-four percent in fact. If the cube were fully live, White could take with as little as twenty percent, but here most cubes for White come after Black rolls non-doubles, and White rolls a big set the first or second time around. Only parlays where both sides start with double-ones lead to somewhat efficient cubes. White must pass, though taking is a small error.

It was double-ones which led me astray. For some reason I was seeing them as giving White full value, while practically destroying Black. Actually, there isn’t that much difference.

 

Both players miss on ones, and after two big numbers, White is ahead only because 11 bears off two men on the deuce, whereas it misses for Black’s one on the three and one on the two. Black’s worst parlay not involving a 21, is to end up with two men on the 3pt, whereas the same set of rolls for White leaves a man on the three and man on the two.

 

Meanwhile, both players waste on deuces, but having hallucinated that the difference in double-aces was a big gain for White, I then inverted the value of missed doubles.

 

 

 

A pure three-roll versus three-roll bearoff (six men on the ace versus six on the ace) is worth 21.22% to the taker. The above position is pure for White, impure for Black. Black does not profit from 11 or 22. This brings White’s chances up to 25.6%, an easy take at money, though a tiny pass at the score, as the cube is worthless.

 

 

White gained 4.39% when Black was spread and he was pure. On that basis you might guess that when the situation is reversed he’d lose 4.39%, and would have 16.83% winning chances. In fact, his chances are only 15.33%. The doubling side usually has three chances to roll, but the taker only has two.

 

Had I not been wrong to begin with, there was room for a different, interesting discussion. There is the Fish Factor. I don’t know Nick’s error rate, but Marty has one of lowest in the world, averaging under 3.0 in the BMAB ratings. Almost everyone playing Marty should consider him the stronger player. When and how to apply the Fish Factor when the game is complicated is often debated, but here there is no need for discussion. These are precisely the sorts of positions the Fish Factor is made for.  According to the table for 50-point rating differences found in Can a Fish Taste Twice As Good? (Available from the lovely Carol Joy Cole at better backgammon tournaments everywhere.) the takepoint for a redouble to four at seven-away, seven-away is 23.45%. That’s the cubeless figure, around 2.5% lower than for evenly matched players. The higher the level of the cube, the more it matters. If a 50-point Elo rating is worth about 1.5 PR, and Marty is playing at under 3.0, anyone not averaging under 4.5 is kidding themselves that this is a take.

Actually, it is even clearer than that. An XG rollout found the position to be a 1.025 pass, or not so far from a coin flip. That’s because there is some value to owning the cube. For the weaker player, the value of owning the cube, and potential to send it at eight, is even greater. The bottom line: Unless your name is Mochy, you should take this cube.

 

Backgammon Super Genius Quiz – Reviewed

 

Take a close look at this position. It’s a money game Take up to one minute to choose your play.

 

 

Your choices are:

a)     15/10, 6/5*

b)     13/8, 6/5*

c)     7/2*, 6/5*

 

I will talk more about this position at the end. I was leery of giving you a position at all, but since this graces the front cover of James Vogl’s Backgammon Super Genius Quiz, you will be prematurely exposed if you buy it, or even if you simply fondle a copy while browsing the boutique at your next tournament.

In the mid-seventies, after beginner books had saturated the backgammon market, authors sought alternatives. The quiz book was born. Joe Dwek’s Backgammon For Profit, which appeared just before Paul Magriel’s Backgammon, was a quiz book, each page a new problem to be solved. Some quiz books were more unabashed, calling themselves quizzes, and offering scoring for the problems solved. While some, especially the easy ones, are more ephemeral than others, since once you have finished the quiz, it feels as though you are done with the book, others repay repeated study.

 

James Vogl’s book is in the latter category. As quizzes go, he has taken the format awfully far. The book comprises one hundred questions, and is divided into ten sections covering different aspects of the game, each with ten questions. That level of organization takes it well past the more typical “here are some problems that came up in my games, and I’ll see if there’s a book in them” efforts. James was just getting started.

He rounded up twelve players, his “super geniuses.” I am not sure I would class them with Albert Einstein, Isaac Newton, and John Von Neumann, but they are sharp guys, and more importantly, excellent backgammon players. The twelve are: Aref Alipour, Bob Wachtel, David Wells, Dirk Scheimann … (I am following the author’s alphabetizing by given name, not surname) …Hideaki Ueda, Joe Russell, Masayuki “Mochy” Mochizuki, Ryan Rebello, Sander Lylloff, Sebastian Wilkinson, Wilcox Snellings, and Zdenek Zizka. If you aren’t sure who all of them are – I wasn’t – there is a long introductory chapter where you are invited to “Meet the Geniuses.” I know seven of them personally, and had heard of some of the others, and so can attest that this is an exceptionally strong group.

They agreed to compete in a timed event, ten minutes for each section of ten questions. I recommend that you read the book the same way. You do not need to do all ten sections at one sitting, giving you a slight advantage on them. But you should get a timer, and time yourself, writing down all your answers. I created a spreadsheet, recording my plays, and later the number correct, the equity lost on incorrect answers, and whether the incorrect answers were errors, or blunders. This matches what James did for his quizzers. By keeping close track of my answers, I will be able to review my errors, searching for patterns, or for particular types of problems where I had a blind spot.

 

After each section, the answers are given. Though not every quizzer commented on every problem (indeed, none commented on every problem) there were always several who had comments, offering their insights into the position. The reader is able to see what answer each quizzer chose, not only whether they got it right or wrong, and totals for the section, as well as running totals are given.

 

These are tough problems! How tough? The best anyone did was 56 correct. Two of the twelve scored 37. I couldn’t match them, scoring just 35. I tied for most blunders (18), and only in the total equity given up did I best a couple of them. I missed a few because I thought “quiz factor,” and a few more because, after reminding myself not to look for a quiz factor, a problem came along which had it. For instance, without giving too much away, there was a problem where my first thought was “I once saw a position like this!” That previous time, the answer was a horribly ugly, anti-positional move. “No, that would be too quiz factory!” But yes, it was the horrible, ugly play.

The problem I set you at the beginning is taken from the first section in the book, problem #10. You should write down your answer, and when you buy the book and take the quiz, give yourself nine minutes for the other nine problems.

The worst answer is 15/10, 6/5*. If you chose that, as five super geniuses did, score yourself with an error, and -.057. If you chose 7/2*, 6/5* you also made an error, -.048. That’s what I did, as did the other seven super geniuses. No one picked 13/8, 6/5*, the best play.

 

What is going on? Why strip the midpoint instead of bringing down the blot from 15/10? Mochy found the best explanation. He looked at the difference in equity between all of the responding rolls. Most numbers show very small swings, but 55 is somewhat large, because he can hit twice, and point. However the killer is 64! Bringing the blot to the 10pt transforms that from poor roll to joker.