Apr 29, 2011

Analysis of the 44 position

First of all, thank you all for the great feedback!

I hope you won't be disappointed with my analysis. As this is the first time I'm doing this, I would appreciate your comments on the analysis – what did you like and, more importantly, what you didn't like and what would you like to change (more variants, deeper analysis, shorter analysis, explanation of some stuff I didn't explain, etc.).

If you are new here, I recommend you to first read previous post before reading any further.

So here is our position once again:
is Player 2

score: 0
pip: 162
Unlimited Game
pip: 167
score: 0

is Player 1
to play 44

Only three candidate moves (three best ones) were chosen by readers:
- 24/20(2) 13/9(2)
- 24/20(2) 8/4*(2)
- 8/4*(2) 6/2(2)

Most votes were for making 20pt and 9pt. I find that not surprising, as this is the best move in most second roll positions where you have 44 to play. But not in this position. Let's see why.

Backgammon players know advanced anchor (made point on your 21pt or 20pt) is important, but usually underestimate how important it is.
Advanced anchor protects you against blitz, as you cannot be closed out, and protects you against prime, as primes in outer board are not as effective as primes which include home board points.
Once you have the advanced anchor, you can concentrate on other parts of the board and you can play more freely knowing you have a safe defensive point.

One of the goals in early game is securing the advanced anchor. And if you look from your opponent's perspective - you want to stop him in his tries to make his advanced anchor.

In our position, he has split his back checkers with 3, 24/21. That means he's only half a roll (one die needed) away from making his 21pt anchor.
If you play "usual 44 move", making 20pt and 9pt, he has all 3's, 21 and 11 to make 21pt, and 41 to make 20pt. That's 16 of 36 rolls (Do you know how to calculate this? Should I explain it in a new post?), after which both you and him will have an advanced anchor - you cannot prime him nor blitz him anymore.

Once your opponent has split to his 21pt or 20pt, don't let him make his advanced anchor! Attack the blot on 4pt or 5pt!

Exercise 1:
Take a look at the original position once again and instead of 44 give yourself any roll containing 2 or 4 - numbers which could hit his checker on 4pt.
Except for 11, 22 and 42, all other rolls could hit but you cannot make a point, so if you hit on 4pt, you're leaving a blot he could hit from a bar and send your third checker back.
Would you hit in those positions? In all, in none, in some of them (which one: 21, 41, 32, 52, 62, 43, 54)?

We are still at our original position, we eliminated 24/20(2) 13/9(2), and now we have two candidates left which both include hitting on 4pt.

Here is the situation after playing 8/4*(2) and now we have the other half of the move to play:
is Player 2

score: 0
pip: 166
Unlimited Game
pip: 159
score: 0

is Player 1
to play 44 (only two 4's)

We must decide between 24/20(2) and 6/2(2).

With 6/2(2) we're closing the third home board point, meaning your opponent will stay on bar 25% of the time (9/36 rolls).

Tip: To calculate the number of rolls which do not enter from bar, just calculate the number of your home board points and square that number.
For 1 point board only one roll doesn't enter; for 2 point board four rolls don't enter; 3pt nine rolls; 4pt sixteen rolls; 5pt twenty-five rolls.

If you make 2pt, you have committed yourself to a blitzing game. But you have only two checkers (third on 6pt and the one on 8pt) who are ready to make new points in your home board, and you can hit the other blot only with 64.
Even if your opponent dances (stays on the bar), you're not ready to launch a powerful blitz.

You are in an even bigger problem if he enters from the bar (36-9 = 27 rolls that do that, 75% of the time) as with most of his rolls he will either make a defensive anchor or cover his 11pt blot.

Now let's consider the other candidate move - 24/20(2).

Now you have only two points in your home board so your opponent will enter easily. (Try to calculate how many rolls is that!)
But, on the plus side, you've made an advanced anchor. And we know how important an advanced anchor is, and what it gives to you and what it takes away from your opponent.

Take a look at the position after you have played 24/20(2) 8/4*(2):
is Player 2

score: 0
pip: 166
Unlimited Game
pip: 151
score: 0

is Player 1
on roll, cube action?

Let's see how some of your opponent's rolls play for him:
With [66, 64, 44] he stays on a bar, but even sixes and fours that enter are not very good for him:
65 - he plays bar/14 or bar/20 24/18, leaving a blot on his 11pt and another one in your outfield
63 and 61 - again he must leave two exposed blots
41 - bar/20 - blot on 11pt and 20pt
42 and 43 - he enters and moves 11/7, again leaving a blot
And some other numbers are also ugly: 51, 31, 11.

In total, there are 21 rolls (every non-double is counted as two rolls, for example: 51 and 15, 31 and 13, etc.) that either not enter or enter and leave many blots.

Also, you're not committed to a blitzing game anymore, as from here you can play any type of game, depending on what will happen in the next rolls.
That leaves you with many different ways you could win this game.

To conclude:

In this position, playing "regular 44 move" 24/20(2) 13/9(2) is a blunder as you give your opponent many rolls that make his advanced anchor.

You must stop him by hitting with 8/4*(2) and decide between [A] 24/20(2) and [B] 6/2(2).
Play [B] commits you to play a blitz in a position where you are not yet prepared for powerful blitz.
Play [A] is not committing (you can play all types of games), advanced anchor is more useful than the 2pt, and your position is very solid.

Correct move:
24/20(2) 8/4*(2)

Exercise 2:
Let's say you have played 8/4*(2) 6/2(2) and your opponent dances. We reach this position:
is Player 2

score: 0
pip: 166
Unlimited Game
pip: 151
score: 0

is Player 1
on roll, cube action?

2.1. Would you double in this position? Is this take or pass? How sure are you in doubling and taking decisions?
2.2. You are now in a blitz mode and your game plan is to keep your opponent on a bar as long as possible. What would you play with: 33, 44, 65?

Before next time, try to answer to the Exercises 1 and 2. (And feel free to criticize my analysis and say what you would like to see improved)


  1. Exercise 1:
    I would hit with 32 (6/4*/1*) because I could hit twice; I would also hit with 21 (24/23 6/4*) because being behind in race a bold play is better.

    Not sure about 52 and 62.

    I would not hit with other 4s because it would be with the wrong checker (the spare on the 8pt instead of one on the 6pt) and because 24/20 would be much better, threatening the blot on the 14pt.

    Exercise 2:
    2.1. I would double but expect a take. I'm more sure about the take than about the double.
    2.2. 24/21(2) 13/10(2), 13/5(2), 13/7 6/1*. Actually for 33 I have no idea, it could be 13/1* or 13/10(2) 13/7 but I don't think blitzing is correct here.

  2. 2.1) Definitely a double. White has an advantage in position, race and threats, and there are many market losing sequences - basically anything with a dance. Perhaps White has lost his market already - I'm not sure, but usually 3 of 3 PR&T is a drop.

    2.2) I'm not convinced that the right "game plan is to keep your opponent on a bar as long as possible". This would imply being willing to hit loose and with only 8 checkers in the zone I don't think a full-on blitz is sound. With 33 I'd make an anchor and bring two down (24/21(2) 13/9(2). With 44 I'd make the 5 point, and with 6/5 I'd bring two down, making the eight point in the process.

  3. Exercise 1

    21 - I'd bring one down from the midpoint and split the backmen 24/23 13/11. There's just not enough checkers in the zone to hit loose.

    23 - Hit 'em both. 6/4*/1*. Anytime you can put two men on the roof it's worth a good look, and it looks correct here.

    25 - Again, there's not enonugh backup to justify the loose hit. Split with 24/22 13/8

    26 - here's where I'd make the tempo play - hit loose and split to the 18. 24/18 6/4*

    41 - This is a hard one, but I don't think I'd hit loose. Split and unstack 24/23 13/9

    43 - Hit 'em both. 8/4*/1*

    54 - Not sure, but the double hit looks favorable. 8/4* 6/1* and hope for the best.

    64 - hit the blot in the outfield while escaping a man. 24/14*

  4. testing Safari 3.12

  5. testing Firefox 3.5.18

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  6. I would say this is double/take, 3-3 i would make my bar, 4-4 make my 5pt, 6-5 i would play 13-7...6-1. will be interesting to see how my choices of play rank against hitting with the 33 and 44. Institute

  7. Exercise 1:
    21, 41, 32, 52, 62, 43, 54

    I would hit loosely for the numbers where I could also bring a builder down for backup to anywhere but the 8 point (the reason is that I already have a builder on the 8 point). So, I would hit with 32, 62, 43, and 54. With 21, 41, 52 it's just too risky because i don't have enough ammunition covering this new blot on my home board.

    Exercise 2.1

    I would not double in this position. I'm not very sure in my doubling and taking decisions, but I don't really have enough ammunition to continue the blitz and my opponent could still make an anchor on my five point now and then we'll be in a holding game which could go well for him. It's just too early to double, I think. My opponent has an easy take.

    2.2. You are now in a blitz mode and your game plan is to keep your opponent on a bar as long as possible. What would you play with: 33, 44, 65?

    well, I don't have enough checkers in the zone for a true blitz. I guess since my goal is to keep the my opponent in the air, I'd play:

    33: 4/1(2), 13/10(2) but that goes counter to my goal of keeping him from developing an advanced anchor and commits me to continuing this ill-fated blitz. the only reason i'm even considering this play is because you said the goal is to keep him in the air. making the bar point is much saner.
    44: 13/5(2)
    55: 13/3(2)

    but I'm not sure I wouldn't just abandon the blitz and make the saner:

    33: 13/7(2)
    44: 24/20(2), 13/9(2)
    55: 13/3(2) (this is the only smart play no matter what)

    blog works fine in Chromium 10.0.648.205 (81283) Ubuntu 10.10, except I keep getting an error message ("We're sorry but we are unable to process your request") when I try to comment with OpenID

  8. excercise 2:

    No double. I'm just one roll away from my opp being the favourite, I guess. Mainly because my checkers on the 24 point are rather far away from the rest. (But I'm never certain about the cube)

    33: No blitz. 24/21(2) 13/10(2)
    44: Not sure. 13/5(2) and hopefully my back men can run next time.
    65: 13/7 13/8. That leaves opp with 10 enter and hit rolls (I think). 13/8 24/18 is too risky. (17 enter and hit rolls, I think) Running a back man 24/13 might be worth looking at. Only 2 enter and hit rolls for opp. I think that's it. I change my mind. with 65 I'd play 24/13.

    Right, now I'm going to see what other people think.

  9. With the second roll double four is it always correct to hit on the 4 point and make an advanced anchor on your opps.20 point? Does it alter if you are on double match point, you need a gammon or want to save a gammon?

    Why is the given answer better than the hit on the four point and making the 9 point to prepare for a blitz. I fully understand the value of the 20 point and the flexability it will give but surely a blitz is possible? And the runners are under no preasure at the moment so can wait to split or run. Or is the 20 point SOOOOOO valuable that it is stupid to miss the oppertunity to make it?

  10. @matt:

    Score is a major factor here.
    At gammon-go (you need a gammon) hitting twice is the best, as it wins most gammons.
    At gammon-save (your opponent needs gammon, you only need one point) making an anchor is very important as that cuts down gammon losses. After that you either hit on 4pt or make 9pt.
    At DMP (both players need only one point, gammons don't count) hitting loses its value so it is only slightly ahead "calm" 20pt+9pt.

    Is 20pt (so) much better than 9pt? Yes it is :)
    Don't forget that your opponent has a blot on 14pt, so 20pt serves both as an anchor and as attackers on that blot. By anchoring, you're blocking his sixes (try to see how to play various sixes for him: 16, 26, 36, 56).
    Also, if your blitz fails, by making 20pt you'll still have a very playable game. If you make 9pt and your blitz fails, you have checkers on 24pt - very far away from home and prone to counter-prime - those checkers could get trapped!

    Hope this helps, and feel free to ask again if something is not clear.

  11. Did you intentionally not mention 6/3 making an anchor?

    Great analyse anyway.

  12. Thanks Miram. excellent explanation about the gammon go, gammon save and dmp, and also very clear now on the 20 point vs 9 point. Many times my blitz has failed and those runners are very dificult to get out if there is any sort of prime in thier way.