Today, most advanced and intermediate players have a pretty good idea about what doubles should be taken and what doubles should be passed.Unfortunately, they are unable to use this evaluation skill to determin ewhen they should be doubling. As a result, most good players double too late, costing themselves opportunities to win two and four points.In this article, I will show how you can use your skill in evaluatingwhether or not a position is a take to determine whether or not you should double.

For any given position, if you are asked what is the correct cube strategy there are four possible answers. They are as follows:

1) Not good enough to double, take
2) Double, take
3) Double, pass
4) Too good to double, pass

If you have the advantage in a position and fail to double when you should, letting the position slide from category 2 to category 3, you have doubled too late. This is called losing your market. Even though you can lock up a sure point by doubling, if your opponent's pass is correct you have cost yourself considerable equity by failing to double earlier. This is the error we are trying to avoid.

Let's play through a few rolls of a game and see how the correctcube strategy changes as the position improves.

1)
Blue: 3-1 8/5, 6/5
White: 5-4 13/9, 13/8

158 163

White money game Blue

What's happening? Should Blue be doubling? This is always the most important question to ask whenever it is your roll if the cube is in the center or on your side. Every roll is a cube decision! The first part of any play, before rolling the dice, is making a conscious decision about whether or not to double. This cannot be emphasized enough. I haveseen many missed doubling opportunities go flying by simply because it never occurred to the player that it might be right to double. A commons cenario is for a player to roll a series of good rolls each of which improves his position, and for him to be so caught up in his good fortunethat he completely forgets about the cube. It is a worthwhile habit to consider doubling before every roll of the dice, regardless of theposition. The position in question here belongs in category (1) in my opinion -- not good enough to double, take. However, it is always worth looking at.

2)
Blue: 6-2 24/16*
White: 5-2 B/18

167 155

White money game Blue

What's happening? Should Blue be doubling? I strongly believe he should.There are many strong sequences for him which will give him a substantialadvantage, and not much bad figures to happen. However, I think Whitehas enough play to justify a take, for if he is hit and hits back orisn't hit and makes the enemy bar point he will have almost an even game,and even if things go badly he has the ace point anchor to fall back onand Blue still has one man to escape. Consequently, I believe this positionfalls into category (2) -- double, take. Shortly I will show how I reachthe conclusion to double.

3)
Blue: 6-5 16/11, 13/7*
White: 4-2 B/23, 13/9

168 144

White money game Blue

Assuming Blue failed to double last time, what's happening now? In my opinion, White no longer has a take. We are in category (3) -- double, pass. Blue has erred by not doubling last time, and he has now lost his market. Even though he locks up a sure point by doubling now, he still wishes he had doubled earlier, for since White has a pass here Blue's equity in playing out the game with White owning a two-cube is higher than one point.

4)
Blue: 2-2 11/7, 6/4(2)
White: 6-3 9/3, 6/3

159 136

White money game Blue

Assuming Blue still has not yet doubled, what is happening here? In thisposition, Blue is too good to double -- he should play on for a gammon.Granted a gammon isn't all that likely with White having an anchor, butBlue's position is so strong that nothing bad can happen next roll, so there is no harm in playing on. This is category (4) -- too good to double, pass.

Now, how do we determine when category (2) -- good enough to double -- hasbeen reached? The procedure is as follows: When considering whether or not to double, walk around the table to the other side of the board (at least do it mentally, since you won't be able to do it physically), and ask yourself the question: If I were doubled in my opponent's position, is it a take?

This is the point where most players make their big mistake. They may doall this, then if they think it is a pass they will double, while if theythink it is a take they will not double. This will lead to doubling way too late in many games. The important thing to realize is that there arenot two possible answers to the question of is it a take -- there are three possible answers. They are as follows:

1) Yes, I'm absolutely sure it is a take
2) No, I'm abslutely sure it is a pass
3) I'm not 100% sure

We now get to Woolsey's Law of Doubling, which may be the most important backgammon principle you will ever learn. It is as follows: If the answer to the "is it a take" question falls into category (3) "I'm not100% sure", then it is ALWAYS correct to double. This applies to money play and to match play. It is true that there are certain exceptions in match play when you are ahead in the match and the turnof the cube will put you out or nearly out, but in all other situationsthe law applies.

Many readers will assume that I am exaggerating. Let me assure you thatI am not exaggerating in the slightest! I repeat: If there is ANYdoubt in your mind as to whether a position is a take or a pass, then itis ALWAYS correct to double. To put it another way: Suppose Magriel or Sylvester or even God came up to you and said: I think thisposition is a pass, and I am willing to pay a point and the cube for thehighest stakes you can afford. If you would not instantly say: "Sit down", then you are not 100% sure, which means you must automatically double.

Let's see why this rule works. If there is some doubt in your mind as towhether it is a take or not, there are several possibilities:

a) Maybe it actually is a pass. I hope most of the readers are sophisticated enough to realize that if you fail to turn the cube when your opponent's correct action is to pass you are costing yourself a ton of equity, regardless of what your opponent will actually do.

b) Maybe your opponent will think it is a pass. Differences of opinion make horse races and backgammon decisions. If there is ANY doubtin your mind, then there is always a possibility that your opponent mayview his position more pessimistically than you and choose to pass thedouble. If you fail to double in such a position you have given youropponent a free roll to get back in the game when you could have collected a sure point, which is extremely expensive.

c) Maybe it is a correct double, even if it is a take and your opponent correctly takes. This is not an unlikely scenario. The fact that youthought there was some possibility that it might be a pass indicatesthat your position is strong and there are undoubtedly a few market-losing sequences. If this is the case, it could easily be correct to double even if your opponent is correctly taking.

d) Worst case -- It is not theoretically correct to double, and youropponent correctly takes. How bad is this? Not very bad. Unless yourassessment of the position is completely off base you still have a clear advantage. True, you have forfeited future use of the cube to your opponent, but you have doubled the stakes with an advantage -- how badcan that be? You will only regret your decision to double if he turnst he game around -- then you will lose twice as much as if you hadn'tdoubled. Since you are the favorite in the game, things are not all that bad.

When I first discovered this principle and started to employ it, I wasastounded at how my results improved, both at tournament and money play.I found myself winning doubled games and gammons that I never would havewon before, because I previously would have waited too long. At the sametime, I collected unexpected points when my opponent passed a double thatI thought he should take (but I was not sure, of course). I was out performing players whose checker play was superior to mine simply becausemy doubles were more timely. These pressure doubles caused opponents to make mistakes -- dropping positions that they should take and taking positionswhich led them to larger losses.

Does this law apply only to initial doubles, or does it apply to redoublesas well? Surprisingly enough, it applies just as strongly to redoubles,for all the same reasons. It is true that it is more costly to sacrificea cube that you own than to sacrifice a center cube when you err and makea theoretically incorrect redouble (and your opponent correctly takes, whichhe might not), but in the long run you will still gain by using the law for redoubles as well as initial doubles.

Let's replay our sample game asking the correct questions:

1)Blue: 3-1 8/5, 6/5
White: 5-4 13/9, 13/8.

Let's walk over to White's side and ask the question: Is it a take? Personally, I am 100% convinced that it is. Blue certainly has the advantage, but if Magriel, Sylvester, or God declared that it was a pass I would unhesitatingly tell them to sit down. As we shall see later justbecause a position is a 100% clear take doesn't necessarily mean that itis not a double, but that is not what we are considering here. The key to the rule is that if it is not a 100% clear take, then it isdefinitely a double.

2)
Blue: 6-2 24/16*
White: 5-2 B/18

Is it a take? I certainly think so. Despite Blue's lead in the raceand in development, White still has all his men in play, is threateningto make an advanced anchor, and is in no immediate danger of beingblitzed or primed. However, the key is that I think it is a take, asopposed to being 100% sure. If Magriel, Sylvester, or God declaredit was a pass and pulled out his wallet, I would certainly pause and givethe position a second look. That is all I need. If there is theslightest doubt in my mind, then it is automaticallycorrect to double, and I need look no further. Readers who have watched me play may notice that I often double a complicated position with apparentlyno thought. What has happened is that I was not able to instantly assessthe position as a take for my opponent, which makes it automatic to double.Maybe he'll take, maybe not, but that is his problem. It is odd but truethat the less sure you are about the position (i.e. whether or not it isa take), the more sure you can be that it is correct to double.

How about when you should be playing for a gammon. Simple -- ask thesame question. Obviously you must think it is a pass, otherwise youwould never consider playing for a gammon. However, you must be 100%sure. If there is the slightest doubt in your mind, then it is nevercorrect to play on -- always double. The reasons are largely the same:

a) Maybe it actually is a take. If there is any doubt in your mind, thenthis is a possibility. Naturally it would be foolish to play on for a gammon when your opponent has a take, regardless of what actual decisionhe makes.

b) Maybe he will take even though it is a pass. Opponents are not infallible. I have several times doubled positions which I had considered playing onfor the gammon, only to have my opponent shock me and take the double.Needless to say, you literally cost yourself double the value of the cubewhen you play for the gammon when your opponent would have taken, sincedoubling would have given you the opportunity to play for the gammon at twice the level of the cube.

c) Maybe it is correct to cash anyway. A position has to be very strong to justify playing on for the gammon. If there was some doubt in yourmind as to whether or not it is a take, it is almost certainly correctto cash.

d) Even if it correct to play on and you mistakenly double and youropponent correctly passes, you usually haven't cost yourself muchin equity. If you thought it might be a take, there must be a fewrolls which will get your opponent back into the game, so the gain fromplaying on can't be much even if it is correct to do so.

I have often heard players attempt to justify not doubling by sayingthat they weren't sure if they were not good enough or too good. This isobviously nonsense most of the time. If they aren't sure if they are good enough they obviously are not sure it is a pass, while if they think they might be too good they obviously aren't sure it is a take. Therefore, by Woolsey's law, they have an automatic double. Following the law willprevent you from falling into this trap -- if you aren't sure about theposition, double.

Let's continue with our sample game:

3)
Blue: 6-5 16/11, 13/7*
White: 4-2 B/23, 13/9

Is it a take? I don't think so. Blue has a strong threat to form afour-prime with three White men trapped behind it. Blue has only oneman back, and White hasn't started to develop his position. However,White has an anchor and still has all his men in play, so there issome doubt in my mind -- I can't be 100% sure it is a pass. Therefore,any thoughts of playing for a gammon are out the window -- Blue mustdouble. Who knows, White might even take.

4)
Blue: 2-2 11/7, 6/4(2)
White: 6-3 9/3, 6/3

Is it a take? Absolutely not! I am 100% sure about this one, and wouldnot hesitate to pay a point to anyone who claimed it was a take.Consequently it is not automatic to double -- Blue can consider playing on for the gammon. As we shall see, playing on in this position is, infact, correct.

Now, let's examine the more difficult question of whether or not to doubleeven though we are 100% sure it is a take. In most positions it is correctto wait a roll. However, there are certain positions which are so volatile that it is imperative to double now. In other words, so much is likelyto happen on the next roll that even though your opponent has a clear takenow there is a good chance that he will have a huge pass on the next roll.In this case, it may well be correct to double now. The most basic example:

2 7

White money game Blue

Obviously this is a take, since White will win 17/36 of the time. However,the position couldn't be more volatile, since the whole game will bedecided by Blue's next roll. Consequently, it is clearly correct for Blueto double. Note the famous Jacoby paradox here -- if White's men were onthe one and four points then it would still be correct to make an initialdouble but not to redouble. The difference is that here the next rolldoesn't decide everything -- Blue still has some life after death if heholds the cube.

Look at the following position reached after this opening sequence:

White: 6-4 24/14
Blue: 5-5 8/3(2), 6/1(2)*
White: --

158 147

White money game Blue

Is it a take? This position has been rolled out by many different players,and take my word for it -- it is a very clear take. However, the positionis so volatile that it is still correct for Blue to double. If Blue hitsWhite's blot and White fans or enters with only one man, or if Bluecontinues to develop and White again fans, White will suddenly have a bigpass. On the other hand, if Blue does nothing special and White entersand brings the man on the 14 point to his outer board it will beanybody's game, with Blue's lead in the race and development compensated forby his early commitment to the ace point and having two men back. No matter.The position is so volatile , and Blue has a reasonable chance of losinghis market by quite a bit on the next sequence of rolls, so it is correctfor Blue to double.

This deceptive position came up several years ago:

103 107

White money game Blue

Should Blue double? Obviously it is a trivial take, since if Blue fails toroll a six the game is up for grabs, and if Blue rolls a horror White becomes instant favorite. However, it is still correct for Blue to double!The point is that if Blue rolls one of his 11 sixes he loses his market bya mile, while if he rolls any other number except 3-3 or 4-4 it is stillanybody's ball game. This is easily enough to justify a double. I played this as a Proposition (double vs. no double) for several hours andslaughtered my opponents.

However, most positions are not as volatile as the above example.In these less volatile positions, it is usually not correct to doubleif your opponent has a clear take, even if you have a reasonableadvantage. For example:

119 107

White money game Blue

A typical five-point holding game. The race is 119 to 107, so White clearlyhas a take on the race alone. In addition, the contact appears to favor White. He will have some chance of getting a shot as Blue attempts toclear his midpoint and his eight point, and Blue will be forced to bear inwith an empty five point until White leaves. These factors should morethan compensate for any difficulty White has leaving the enemy five point.Consequently, it is a trivial take. Should Blue double anyway? No. Thereis not enough volatility in the position. Blue needs to roll a set to makegreat headway on the next roll, and only 5-5 or 6-6 really give Whitea big pass -- after 3-3 or 4-4 White will probably have a pass, but it will be close so Blue won't lose his market by much if at all. On the downside,if White rolls the big set the game will be a tossup. Since Blue is veryunlikely to lose his market by a lot, he should wait.

Finally, let's examine playing for the gammon. As we have seen, it must be 100% that your opponent has a pass -- if not, it is always correct todoublt. Who knows, he might even take! Assuming that the pass is 100%,it is quite often correct to play for the gammon. Here, many playersmake a serious error. The first question they ask is: How good are my gammon chances? While this can be an important factor, it is not themost important one. More important is the following question: Is therea reasonable possibility that, on the next sequence (that is I roll, he rolls), the position can swing so much that my opponent now has a cleartake? If the answer is no, then playing for the gammon is mandatory. Here is a common example which I have seen experts misplay:

78 71

White money game Blue

Should Blue double? Obviously White has a clear pass, so playing for thegammon can be considered. Admittedly Blue's gammon chances are slim, butthat is irelevant. The Key Point is that there is nothing that Blue canroll on his next roll that will give White a take, so going for the gammonis clearcut. If the spare man on the six point were on the five point thenthere would be some risk in playing of (6-6 by Blue, any 6 by White), sowhether or not to play on would become a moot point. In the actual position,it is clear. It should be emphasized that Blue does not commit himself to play for the gammon to the end just because he take a roll here. Every roll is a cube decision! After each roll, Blue must reevaluate the position,and if there is a chance of leaving a shot it might well be correct to cash.However, as long as Blue cannot leave a shot on the next roll it is clear toplay on. This is another common error by many players. They decide to play for a gammon, and continue to do so regardless of what happens. Each individual position must be analyzed before every roll and a new decision about the cube must be made. This is very difficult to do, which mayexplain why many players fail to play for the gammon when they should, butit must be done if you are to make the most out of the cube.

For another example, consider the resulting position after the fourth rollof our sample game, where Blue has completed his five-prime. Clearly, Whitemust pass if Blue should double. Also, nothing really bad can happen toBlue on the next sequence. Give White his best sequence, and he will haveat best a marginal take. Consequently Blue should play on for a gammon, even though he probably won't get it since White already has an anchor andhas a chance to advance his anchor. However, if on the next roll Blue does nothing special and White either makes Blue's three point or starts to develop his own board by making his five or four point, then Blue should five serious consideration to cashing, for if White makes one additional improvement he could well move into take land. As always, before every roll Blue must make the big decision of whether or not to double.

112 56

White money game Blue

Clearly White has a pass if Blue doubles. Should Blue play on? I think not. There is an immediate disaster sequence (6-4 by Blue, hit by White), and thereare likely to be problems later. Here is is of importance that Blue's gammonchances aren't all that good, since White has most of his men in and Blue is facing a possible disaster immediately. If White had more men out in the outfield it might well be worth playing on. Note that if Blue's fourth man on the five point were on the six point instead, it would be correctto play on. Now, nothing bad can happen immediately. Admittedly something like double-fours would leave a very awkward position, but that wouldn't matter. Blue would then double, and White could still not afford to take. The point is that if Blue were to roll double-sixes and White rolled nothing special Blue might now decide that his gammon chances are worth riskinglosing the game and play on, while if anything else happens Blue can justcash, so there would be nothing to lose by playing on for a roll.