the dorbel daily

Wednesday 31 August 2011

One From The Vaults.

Back in the Old Days, before the bots took over the task of teaching the world to play good backgammon, there were expert players and analysts who presented their matches for us, so that we could learn. How good were these players? How good were the analysts? Just running their matches through a modern bot and looking at numbers, they weren't great. Considering that they learned to play without all the aids that we have, they were terrific!
In the next few posts I am going to look at a match played in Monte Carlo in 1981. The players were both at the top of the tree in those days, Stanley Tomchin and Chuck Papazian. We have the match because it was recorded and annotated by Kent Goulding in his series "Backgammon with the Champs." Let me say before we start though, that no comments that I make about the plays or Kent's commentary are in any way intended to poke fun. These were great players and the analysis is terrific. We stand today on the shoulders of giants.

Play in those days was different. The checker play was very pure, concentrating on keeping all your checkers in play much as we do now in dmp games. They slotted the 5pt a lot, noticeably with an opening 6-2 as well as aces and an opening 5-3 was played 13/8, 13/10 by most people. These plays are occasionally seen even today, although now known to be weak. Oddly neither of the players in this match minded hitting on the ace point, but usually only as a diversion. They didn't like to actually make it. In general though, their checker play was excellent, but in comparison to modern players their cube action was poor, with both players passing a lot of easy takes. This 19 point match lasted for 27 games because so many games finished at the 1 level.

It's Game One. Papazian (White) has a 4-1 to play. How would you handle it?

Position ID: mGfwATCYZ/ABMA

I expect (and hope) that you picked 13/9, 24/23, unstack and split. White went for 13/9, 6/5 because that was the way that they played then, with a big emphasis on making the 5pt and building a prime. Can we say why that is wrong? It comits to one plan, building a prime, at considerable risk of being hit. The modern play is much more flexible, allowing White to develop one of several different game plans depending on what the dice provide next, without the same degree of risk. You could of course play 13/8 entirely risk free as far as being hit is concerned, but no more flexible next turn than it is now. That would be an error.
Many players in assessing the risk of a slot count only how many shots it takes to hit that blot. It's as important, perhaps even more important to count how much you lose when hit. If you slot the 5pt here and get hit, you lose 20 pips immediately and given that 11% of the time you then fan with four of your biggest numbers, 6-6, 4-4 and 6-4, a hit loses you three full rolls on average! That's a lot in a game that is at heart a race. How bad is the play? It costs you just about 1/10th of a point compared to the split play. That's a big error. KG thought that the split was a reasonable alternative, so we can deduce that slotting was widely regarded as the standard then for this sort of situation.

Well Black did hit and White did fan, producing this position with Black on roll. Before reading on, what's the correct cube action for both sides?

Position ID: WGfwAFiYZ/ARIA
Match ID: cAlgAgAAAAAA

Black (Tomchin) decided not to double. This is correct, although he is nearly in the window. KG nailed this one, saying that giving away the cube was too big a price to pay for the small number of market losers. Would you double this? In the first game of a long match there's a lot to be said for a very aggressive double like this. Black will win about 62% from here including 24 gammons, to go 2-0 or 4-0 up. If things go White's way, Black will find out how well White uses a 4 cube, extremely valuable information at the start of a long match. Last but not least, you may get a pass! I've seen weaker doubles than this dropped. There are some later on in this match.

Later, White has to play 1-1 from the bar. What would you do?

Position ID: mLfgESBYZ/AAWA

As a fanatical primer, Papazian entered and made the bar and the 5pt. The modern players, knowing that three checkers on the 24pt is deathly will probably make the 23 and 5pts and they'd be right. Improving the 8pt to the 7pt isn't hugely stronger anyway.

A little while later the game moved on to the sort of priming battle that so often occurred then, because of the way that they played. Black is on roll. Is this the sort of thing that you double? As White, would you take?

Position ID: 2G7BADTYbsEDIA
Match ID: cAlgAgAAAAAA

Black doubled, White took, correct action on both sides. The primes are identical, but Black has two extra outfield checkers to play with, which will mean that he will win the priming battle all other things being equal, because White will usually bust his prime first. White still has a lot of play himself though and note that cube ownership is very valuable indeed in prime/prime games, with the ever present possibility of the doubler going bust at any moment with a large awkward doublet. Also, White is at least anchored and can usually fall back on an ace point game if nothing else. KG thought that the take/pass decision was close and came down on the side of pass. That is a blunder, but an understandable one I think.

In this next position, Papazian (White) has to play 6-4.

Position ID: 2G6DAyDYbsEANA

So fanatical were they in sticking to their plan, White plays 13/7, 13/9 here. Today, everybody would make the 2pt without even thinking about it. No shots, makes a point, preserves the midpoint, what's not to like? This play and the play of 1-1 earlier drew no comment from KG, indicating clearly that this was the accepted way to play, pure, brave and stick to your plan.
Modern players need to be more adaptable, switching from one plan to another as needed, often several times in a game!

I'd hate to show you just mistakes. See if you can find Tomchin's lovely play in this position, Black to play 5-2.

Position ID: atsEADbY7TYBAA

He played the elegant 11/6, 5/3, well ahead of any other play. White won't hit even if he does throw a 1, so the perfect slot, risk free, efficient and safe next turn.

We'll look some more at this fascinating match tomorrow. Until then, enjoy the game!

Note: I've switched back to using Gnu boards and ID's, as Gnu users by far outnumber ExtremeGammon users at present. However, I am using EG for the analysis. I'll let you know if it is ever widely different to Gnu.

Saturday 27 August 2011

Fibs Holiday Answers.

Well big thanks to both the readers who posted comments for us and smaller thanks to those who gave me their answers on Fibs and no thanks at all to those who couldn't be bothered! This is not a Dark Ride, you need to participate!

Position One


Black leads 4-0 to 5, Crawford.

Just sitting on this position with an ultra quiet play, 24/22, 16/13 is not really an option. Black does need to hit White off the 4pt, as you usually do when your opponent has a blot at the edge of your prime. You want to make it and you don't want her to make it. Black can't be doubled and loses hardly anything by being gammoned, so he should be playing with a lot of freedom anyway. There are three plays that are slightly better than the quiet play, 8/5, 6/4*, 16/13, 6/4* and 6/4*/1*, all very small errors costing about 0.03ppg. I wouldn't argue with any of these plays if a doubles partner wanted to make them, but the standout best play is 24/21, 6/4*.
Phew, five blots, can it be right? It can here because White is unusually short of checkers to attack, with only seven checkers in the zone and an awkward stack on the midpoint. This maximises Black's opportunities at the back, with enhanced chances to anchor, escape or hit in the outfield as the dice dictate, at a time when White can't mount the sort of response that usually inhibits such a wide open play.

Position Two


The same game later. Actually this isn't too hard. 24/22, 13/9* is best, hitting and improving the anchor. My student played 13/9*, 8/6 but our correspondents didn't fall for that. If you did, 8/6 looks more flexible for the attack, but with only eight checkers in the zone that attack isn't coming soon and Black doesn't really want to break the 8pt to hit. Also, that spare may be useful to make the bar, so it has a dual purpose where it is. Three checkers back always argues powerfully for a high anchor anyway.

Position Three


Same game.

This is a tough play to find. I instinctively liked 16/10, 13/10. It's usually good to make the point six pips away from the opponent's anchor. That play is just about equal with 22/16, 6/3* and both are well ahead of anything else! Phew again, what is going on here? Leaving your anchor and hitting loose behind White's anchor, with the race evenly poised and White having a stronger board! Sometimes answers defy my ability to analyse even with hindsight, so if anybody has any clues about this one I'd be pleased to hear them.
Here's what I think. White's shortage of any spares anywhere near her home board and the blot on her 2pt are of course factors which make the loose hit less dangerous than it otherwise might be, but you do have to ask, what does Black gain from this risk? It's this. Neither side at present has any points made in the outfields, apart from the midpoints and this is a big positional weakness for both sides. Either of the best plays remedies this for Black and with the game so evenly poised, it's hard to say whether the defensive 16pt or the attacking 10pt are going to be more useful.
Even when games reach this sort of tense stand-off, with a hard play every turn, we must keep trying to address severe positional weaknesses, even at the cost of some risk. If we don't do that when we can, then the game will only get harder as it goes on.
I learned a lot from these positions and if you did too, then it's well worth the effort. Keep writing in those that do and start writing in those that don't! It's a better blog with your contribution!

On August 31st at 2300UTC on GridGammon, two of the elite will go head to head for a 13pt IIBGF match. They are Matvey "Falafel" Natanzon of Israel and Mochizuki "Mochy" Masayuki of Japan. This match will be recorded, annotated by me and comments from both these players will be added. It will be available with the annotation and comments as an XG file for $10 or as a Word doc. for $15. Versions as Gnu or Snowie files can also be made if there is a demand at $10.
This is your chance to see how the very best players in the world think and play. It should be a terrific learning aid.

Enjoy the game!

Thursday 25 August 2011

The Fibs Holiday Quiz

Sorry to have been away so long. I occasionally have to interrupt backgammon for life!

Here are three nice checker play problems for you, taken from a recent lesson. As an experiment, I am using my new toy eXtremeGammon to make the diagrams. Hope you like them, but if you don't I can easily revert to the old wooden boards.

Position One

White lead 4-0 to 5 and it's the Crawford game. Black is on roll. Several plays suggest themselves, what do you like?

Position Two

Same game a bit later on, Black has a 4-2 to play.

Position Three

.......and still in the Crawford game, Black to play 6-3.

Answers please, but as ever, your reasoning is much more valuable than the right play!
Enjoy the game!

Thursday 18 August 2011

Japanese Cube Answers

Well, thanks to the indefatigable ah-clem for giving us his thoughts. Let's see how his judgements compare with those of these top-class Japanese players and with the bot analysis.

Position 1

0-0 to 23, Black (Mochy) on roll and he doubled this and White (Suzuki) took. This is actually a bit early, a small error by Mochy. Black has three men back against White's one, which is a weakness and also trails in the race by 10 pips before the roll. Why then is such a great player doubling? Well he has the 6-5-4pts made while White has made nothing yet and he is also looking at White's very awkward stacks on the 8 and 6pts. This could easily go very wrong for White very fast and the momentum to be gained by winning a doubled gammon in the first game is valuable. If things do go White's way, Black is also going to find out how well White uses the cube, very valuable knowledge. With Black's high anchor to insure against an immediate bad sequence, I still like this double even though technically it is a bit light.

Position 2

Of all mid-game positions, I find prime v. prime to be the hardest to evaluate, or even analyse coherently. Let's try! I think White's double is absolutely clear. He has one man back against three, he is shooting at a blot, he already has a five prime and if he doesn't hit, he has three checkers in the outfield that he can fiddle around with while he waits for Black's front position to crumble. In technical terms, White is said to have better timing. What does Black have going for him to justify a take? Well he is anchored at the edge of White's prime, he has a great board and he still has a potential six prime of is own. You also need to add to this the fact that cube ownership is more valuable in prime/prime battles than in any other form of the game. This is because one bad roll can see you go from underdog to favourite in a moment. Double/take is correct and that is what happened in the match.

Position 3

Black didn't double this, not sure why! 23 numbers put White in the air against a four point board. Anything that doesn't hit is an above average racing roll of 9 pips or better and gives Black a nice race lead with a high anchor. White's distribution is also very poor, but it's still an easy take. He's in good shape after the non hit numbers and will be a favourite to enter even if hit. Look out for positions that have this level of volatility, they cry out for a double. Double and Take.

Position 4.

White must double this but Black can still take. He is anchored and anything may yet happen. Both sides have three blots, so it is extremely volatile, like the previous position. Double and Take.

Position 5

White has a huge race lead here but Black should redouble and this is already a clear pass! Why is Black's position so strong? If we look at what White needs to do to win it will give us a clue. He needs to enter, escape and make his way through an outfield which Black is about to flood with hitters. His task may get even harder if he enters with 1-4, 2-4, 2-3 or 2-4 and has to expose another blot and harder still if Black can make his bar point or 8pt. In effect, Black's position will get stronger roll by roll while White's gets weaker. Black didn't redouble, White danced, Black then did redouble and got a take in a position that is an even bigger pass of course, so Mochy's conservatism paid off big time. Redouble and pass is correct.
So there you have it, ah_clem made some mistakes but the 2010 world champion made some mistakes and so did the 2011 champion, so perhaps we shouldn't be too tough on him! I hope you found these interesting, as I did.
Hard game backgammon! Until the next post, enjoy playing it!

Friday 12 August 2011

Japanese Cubes

I have been lucky enough to get the file of the World Championship semi-final between Takumitsu Suzuki, the eventual champion and Mochizuki Masayouki, the defending champion from 2010. Astonishingly they went to the same High School where they knew each other through chess, although Mochy is the older by two years.

Let's take a look at some of the cube decisions. Here are five of them for you to think about for a day or two.

This is the first game of a 23 point match and Black (Mochy) is on roll.

Position ID: 4PMxAwjYnsEAIw


Cube action for both sides?

Position 2 is a bit harder, White (Susuki) is on roll. Black leads 2-0/23

Position ID: bFsjABa4bRMDIA


Cube action?

Position 3, another "easy" one, or is it? It's 2-2/23 now and Black is on roll.

Position ID: mLkwwCnM5sgBCQ

Cube action?

Position 4. Black leads 3-2/23 now and it is White on roll.

Position ID: mLkwwCnM5sgBCQ


Cube action?

Lastly for today, Position 5. It's the same game and Black is on roll and White is on the bar. Black owns the cube.

Position ID: 7z0DAEBsN8gABw

Cube action?

If you can get all of these right for both sides, you can be very proud of yourself. Give it a go and let us know your reasoning too. I ask for this for two reasons. First, you may well think of something I haven't thought of which is good of course. Second though, being able to assemble your thoughts and say why you want to do what you want to do is a key skill that will help you play better in real life. Watch a top doubles team in action. Listen to their reasoning. Imitate it.

I'll give you the answers to these in a day or two, until then, as ever, enjoy the game!

Wednesday 10 August 2011

Quiz Time Answers

All right, I know it isn't Friday, but you've had long enough. Thanks to those who used the comment feature for their thoughts and also those who gave me their answers on Fibs.

Position One.

Here's a very useful tip. "It's usually worth leaving an outfield blot if you can use the roll to make a good point inboard". 13/5(2) puts some teeth into Black's board and will make White very wary of plays that leave blots. If you don't make this play and instead pick up your blot with something like 13/9(2), 8/4, 6/2, White will cheerfully attack your straggler with anything she can find to throw at it. In addition, you have burned your spare on the 6pt and stacked a fifth checker on the 4pt, so you have more or less trashed your chances of ever making a strong board in future. Politicians learn, "It's the economy stupid". We might say, "It's the board stupid". Make it and don't break it.

Position 2.

This one took me by surprise. If it isn't a quiz it takes a very strong minded player to look for something else after 24/13 and a very skilful player to identify the right play.
Here are the steps. Black still trails by 15 pips after the roll, so a racing play is NOT indicated. 13/11 adds a sixth checker to a point that is already fat. I know we do that on the opening roll, but then we lead by 11 checkers after the roll. Here we can find a much better play and it is 13/7, 13/8. This unstacks and puts two very useful checkers into the zone. White's 16 hitting numbers hurt much less than usual because of that big gap in the middle of her board.
Running does nothing to apply pressure on White. It doesn't try to rectify Black's severe positional defects, in fact it makes them worse. A third alternate is the old Kent Goulding play, 24/18, 13/8, which bids to make a high anchor or exchange hits, but this is weaker than running. When it works, Black still has to put his frontal position together, when it doesn't, you get cubed.
What can we learn from this? We still need to address severe positional defects (stripped 8pt, stacked midpoint), even when we are behind in the race and outboarded, in fact particularly then, otherwise the game just drifts away.

Position 3.

Dang, missed everything, can't make a point, what shall I do, run? 24/20, 13/8? Actually though, Black hasn't missed everything. Hitting loose on the ace point is not a play anybody likes to be seen making, but there are times when you have to turn Mother's picture to the wall and do the ugly thing. 24/20, 6/1* is the best play. This is entirely a diversionary play designed to take away half of White's next roll. You won't achieve much by it, because either she hits it (bad) or she misses it (also bad), but at least you've slowed her down a bit, given her a a few awkward rolls and defused some of her jokers.

Position 4.

Black here is me and yes I played 13/3 but the wide open 13/7, 6/2* is best, by a lot. It leaves 23 shots and three blots but Black is anchored at the edge of White's front-loaded prime, so a few more checkers back isn't too bad. Be bold, when it works it's terrific, when it doesn't you're not dead. I wimped it, don't do as I did, do as I tell you. Fortune favours the brave.

Position 5

White lead, 8-6 to 9.

This one shouldn't keep us long, hitting is hugely correct, stopping White from anchoring and going for the closeout. This isn't always correct; if White's board was stronger then making the bar and attacking later could well be better, but here with White's blot on the 5pt and two point board Black has to blitz. Again Black is me and another pretty poor play as I played bar/23, 13/7. If you find yourself prone to these, perhaps like me you are too influenced by recent events. If I've been hit a lot lately and seen a lot of big turnarounds I tend to make these non-comittal plays and hope that the match will somehow win itself, which actually here it did, but that isn't the point. Try to approach each position with a clean slate in a nice objective way. Good trick if you can do it!

I do hope you learned something here, I certainly did. I'll try to find you something interesting for tomorrow. I have eXtreme gammon now, which is nice, but I'll keep on using this wooden Gnu board for the diagrams if that's ok with all of you. I can't say I like the XG graphics so much.

Enjoy the game!

Monday 8 August 2011

Quiz Time

Let's have a little quiz to start the week. All of these have some interest, none are easy. Don't assume that because it is a quiz that the obvious answer must be wrong! Just make the move that you would make over the board, with a little extra thought perhaps and let me know what you think. I'll post the answers on Friday.

Position 1

Position ID: w24TgwDsOcEDCA
It's 0-0 to 7.

Position 2

Position ID: Np7BATCwZ/ABMA
Black leads 1-0 to 7

Position 3

Position ID: 4HPhQSDgc/ABMA
White leads 2-1 to 7

Position 4

Position ID: cLfBCRCsPeAAIw
Black leads 3-1 to 7

Position 5

White leads 8-6 to 9
Both White and Black are on the bar and White owns the cube.

Brave enough to try these and give us your reasoning? Use that comments bit at the bottom, answers on Friday, until then enjoy the game.