If your concern was a 62 or 64 then your move really wasn’t good. Your move doesn’t actually block 64. Your move blocks 62 and 65, but XGs blocks 54 and 44, while yours does not. The increase in blocking from your move is really minimal. (Only 1/36 increase in probability of blocking opponent)

Now if your concern is that 62 or 64 hits your blot after XGs move, that’s really not a primary concern in this position. You are behind in the race; your opponent likely will win if he escapes his back checker. That’s true whether or not he hits your blot. Getting hit might actually be better if he escapes. He’s got a direct shot on his five point, and two indirect shots in his outfield, plus the back checker that you might be able to hit as well. There are quite a few return shots for you after you get hit, and some really good rolls where you can hit two blots.

Obviously when he rolls his 65 perfecta, you’ll wish you had made the bar, but you’re not really blocking that much less, and your position is much better after making the five point.

Ah you're right there. With my move, he can also get out with 54. I missed that one.

"plus the back checker that you might be able to hit as well" - please can you clarify?

As I'm losing in the race, it almost seems like XG is saying I need to get hit to have any chance of winning here. That's how I'm interpreting this now...hopefully that's correct.

I just meant that if you’re hit, you could hit your opponent’s partially escaped back checker as well as the three on his side of the board. Potentially, if you play it well and get a bit of luck, you could end up closing out four of your opponent’s checkers if you are hit.

It’s not that you must get hit to win. You could easily win by containing your opponent’s back checker and closing it out without ever being hit. What you want though is to get hit if your opponent escapes that checker. If he escapes without hitting you, you have little chance. Essentially there are three possibilities. In order by how favorable to you these are

1 His checker does not escape and you close it out.
2 He escapes but hits you while doing so
3 He escapes without hitting.

Your chances in scenario 3 are poor, so XG tells you to leave blots on points your opponent might use to escape (making 2 more likely) and at the same time making an important inner board point (making 1 more likely).

Great explanation! Thank you

XG wants me to play an opening 64 as 24/14, instead of 24/18 13/9. I thought the latter was the preferred opening move?

Actually 24/18 13/9, 24/14, and 8/2 6/2 are fairly close alternatives for an opening 64. As I discussed in an earlier post, different match scores can make winning a gammon more or less valuable. Match scores also can make avoiding losing a gammon valuable (I.e. gammons are valuable for your opponent). The standard 24/18 13/9 play is neutral in that regard. 24/14 is best at gammon save scores (when you should be trying to avoid losing gammon). 8/2 6/2 is best at gammon go scores (when winning a gammon is more valuable).

I’m not sure if that’s what’s going on here or not. It may just be very close and XG is giving you 24/13 based only on the analysis settings. An analysis with a greater number of plies or a full rollout might well change the best move.

Thanks coach

I was playing a game against someone earlier (just on a phone app) and they had an interesting strategy, which you do see now and then.

Their strategy was to hit absolutely everything in their home board, so that I took their checkers and sent them back to my home board. It looked something like this mid game, and then end game.

This strategy is quite effective to be honest...the games can take a while but then they always end up hitting you and then being favourite as they have so many anchors in your home board it's inevitable.

How do you combat this strategy?




End game

This type of position, where one player has 2 or more anchors is their opponent's home board, is called a backgame. Backgames are very difficult to play, from either side, and a lot has been written about them. However, one simple rule (which is way oversimplified, of course) is that once the opponent has made 2 points in your home board, you stop hitting outside checkers to avoid bringing in more checkers into your home board. Your midgame position shows 7 opposing checkers and 3 anchors in your home board, which is a sign that you probably hit too much.

I'm told that once upon a time, many people adopted this strategy of "playing for the backgame", but eventually experts figured out how to defend against it so you don't see it that much nowadays. But if you're not familiar with it, it can be very effective against you.

Thanks grape, I knew there was a name for it. I'll go do some reading on it. Yes it was very difficult to play against!

Played against someone this morning who tried a back game and I backgammoned them!

Can anyone explain why this is the best move here? It seems so risky. Is it because a high risk move is needed as I'm currently in a losing position?

There's a concept that comes back regularly in Backgammon: pay now or pay later. Sooner or later, you will have to move those back checkers. I think it's better now while your opponent has only a 2-pt board. With the suggested move, it will be tempting for him to hit you "loose" (which means while also leaving a blot in his home board), but you don't mind since you currently outboard him 3 to 2.

Basically, pay now if his situation will get better next few turns.
Pay letter if it will get worse next few turns.
Here, he can improve to a 3-pt board or better with 4-2, 5-3, 6-4, 2-2, 3-3, 4-4, 5-5, 6-6 for a total of 11/36 possibilities. Sure, he might not want to make another inner board points for all these rolls, but the option is certainly there, so there is some danger.

Also, if you play a safe move like 13/8, you'll be in trouble soon.

24/21 13/11 is tempting, but that blot could possibly be scooped if he hits you and you dance a roll or two.

Thanks uber. I think I played 13/8 and I certainly paid later..!

Can you clarify this part please? "but you don't mind since you currently outboard him 3 to 2."


"Here, he can improve to a 3-pt board or better with 4-2, 5-3, 6-4, 2-2, 3-3, 4-4, 5-5, 6-6 for a total of 11/36 possibilities."

Okay, so basically with XG's suggested move, I'm only in danger or worse off about 30% of the time. And from what you said above, the longer I wait, the worse my situation will get. Makes sense.

Another question..

Is there a reason why XG is suggesting the move that has a lower probability of winning and lower probably of a gammon..?

Whenever you see an apparent discrepancy like this, it is related to the doubling cube.

The percentages for wins, gammons, backgammons you see reported are for *cubeless* play, if the game were always played all the way out to the end. However, in practice, you have a cube in play. This means that:

1. You might win more often than the cubeless numbers, because you double and opponent passes, saving you some losses you would have had cubeless.

2. You might win fewer gammons than the cubeless numbers. These are called "phantom gammons" (I believe Robertie used this term in some other thread on this forum). Phantom gammons are gammons that happen in cubeless play, but don't happen when there is a cube because you reach some intermediate position where it is too risky to continue and your optimal strategy is double/pass.

One way you can confirm this issue is to setup the same position in DMP (1-point match) and see what XG's recommendations are.

The problem here is that it's a money game with Jacoby in effect. If the cube were on Black's side where it belongs, the right play would be the standard 6/3 5/off. But here, White will double Black out after either play whenever he leaves a shot and isn't hit (or so XG assumes). But if White plays 6/off 3/off and Black rolls 2-2, he loses his 3-point and now the proper cube action is double-pass. If White makes the standard play of 6/3 5/off and Black rolls 4-4, it's not even a double for White.

Basically nothing to learn here because the cube isn't where it should be.

Thanks for the replies. My cube game definitely needs work.

I set it up as a match and the results did come out the same - is that expected?

To be honest, I think all of this is stretching my knowledge of the game now, so to simplify this a little - is it correct in saying that if the doubling cube is on the "wrong" side, then XG's suggested move, when the margins are this tight, won't necessarily be correct?

Robertie, you mentioned the following board. This is still a double now for white? And still a double if black had rolled 62 or 21?

I meant that you had 3 made points in your home board compared to only 2 for him in his own home board.

First, I would say that the best thing you can learn from the game where this position occurred, is to go back earlier and find the point at which you should have doubled.

Also, your diagram is not correct after the opponent's 22 roll. The opponent plays 24/22(2) 3/1(2) so the two checkers on the opponent's 3 point should be on the 1 point. This reduces your dancing numbers from 9 to 4 so it makes a significant difference.

XG's move is correct under the specific circumstances you have presented it. However, it won't necessarily be the correct move when the same position is reached under "normal" circumstances, i.e., when you doubled earlier and the cube is on the other side.

Thanks uber, understood now.

And thanks again grape. Yes that was me updating the board a bit late at night!

Hi again pros

is anyone able to explain why the double hit of 8/4 4/1 isn't the preferred move here? I would've thought that's a stronger move than getting an anchor on the 3 point.

8/4*/1* starts a point you don't want, leaves a blot, and doesn't make an anchor.

8/4* 24/21 makes the best defensive point. That point is even more valuable since Black has already made his 5-point. The play also starts the 4-point, which White wants, instead of the 1-point, which he doesn't want.

Thank you Bill, that makes sense.

My mistake, I meant an anchor on the 4 point, not 3 point.

Is it very rare that you would ever play a checker to your 1 point in the mid game? Sometimes it looks like the best move to me, but perhaps I need to take the risk being hit outfield rather than losing a checker to the 1 (or even 2) point.

I wouldn’t go that far to say you rarely want to move to a low point, but you do need a good reason for doing so. For example, in the position you posted you only have one home board point made. If instead you had the 3,5, and 6 points made, the double hit would be a much better play even though it leaves a checker on the 1 point.

The basic idea is “what is your game plan for winning this game?” There are three main game plans you should be trying to use to win. The dice will often dictate which is best, and things will often not go smoothly (which is where backgames, holding games, and low anchor games come into play), but you should always be looking to do one of these three:

1. Racing - the simplest one to understand. Get your checkers around and off as fast as you can.

2. Priming - make points in front of your opponent’s back checkers and prevent them from moving while you escape your own back checkers.

3. Attacking - hit your opponent’s checkers and make all your home board points thereby preventing him from moving.

The low points (especially the 1 and 2 points) are really only valuable for plan 3. If you’re planning to attack, all home board points are valuable- they all represent one more number that makes your opponent dance when hit.

For the other plans, though, checkers on the low points are harmful to your plan. This is obvious for plan 2. Checkers on your 1 point cannot block your opponent’s checkers. Checkers on the 2 are useless if he advances those checkers.

For racing, though, they aren’t desirable either. This is less obvious, but racing games often lead to positions where contact is broken and you are trying to bear off more quickly than your opponent. Once contact is broken, the dice determine your remaining pip count, but not all positions with the same pop count have the same winning chances. Generally bear off positions with most of your checkers on the 4, 5 and 6 points result in better winning chances than positions with the same pip count and checkers on lower points.

The main idea is wastage of pips. If all your checked are on the 1 point, you can only reduce your remaining pip count by 2 pips (4 with a double) regardless of what you roll. Roll a 65 - you wasted 9 pips. Roll 66 - 20 pips wasted. Keeping checkers on the 4,5 and 6 points prevent wastage.

Therefore, if you are ready to commit to an attack (like you would be in your posted position with 3 or 4 made home board points), you should avoid moving checkers to deep home board points.

Excellent explanation by stremba70 as usual.