Doubling in backgames

Just like how I struggled to even describe backgames in its game plan article, it was challenging to come up with reasonable rules of thumb for cube action in backgames. There simply isn’t anything as neat and tidy as “double with a 14 pip lead.” However, a true 101 course would feel incomplete without at least some cursory guidance on this topic, so let’s do our best.

The first thing to note is that a backgame isn’t a true backgame without 2 anchors. Notably, a defensive position with one anchor and a goalkeeper still only counts as a holding game. The reason for this distinction is that a goalkeeper can be pointed on, and therefore doesn’t compel the same number of uncomfortable rolls as a second anchor would. 

The second important criterion is to have sufficient timing. It’s utterly critical for the trailer to preserve a prime in their home board so that they can trap any checkers sent back. Therefore, counter-intuitively, taking a cube when defending a backgame requires trailing by some minimum number of pips. With too small a pip count deficit, backgame cubes should be passed.

The required pip difference changes dramatically depending on which 2 anchors the defender is holding. Deeper anchors (say, a 1–2 backgame) need way more timing to avoid crunching compared to a shallower backgame, such as a 2–4. Also, backgames where the anchors have 1 gap between them are generally preferred to consecutive anchors, as they lead to more awkward bear-ins. This aspect of backgame cube action needs to be studied, but the table below makes for a good starting point:

Anchors	Trailing pips
1–2	90
1–3 or 1–4	60
2–3, 2–4, or 2–5	50

This table roughly lists the minimum number of pips by which you need to trail in order to take a cube in a backgame. In addition to which anchors are being held, the flexibility of the leader’s spare checkers, which points they are still occupying, and the purity of the defender’s prime also make contributions to these tallies. We can summarize all of these considerations with some good beginner advice: if you are trailing by a lot and are holding 2 good anchors, just take the cube and don’t overthink it.

When to double is a little more straightforward. You shouldn’t think about it until all of your checkers are free and ready to be borne into your home board. Once your backcheckers and midpoint checkers are cleared, you should count the number of points you are occupying in front of your opponent’s anchors. You must wait for the moment when you have 3 points remaining to double:

The two positions above act as a fairly good reference for this class of positions. In both cases, Gary is trailing by about 100 pips in a 1-3 backgame, so he would likely take. However, we should only double in the position on the left-hand side, where we are occupying 3 points (the 4-, 5-, and 6-pt) in front of both anchors. On the right-hand side, we are still in “No double” territory. Don’t be impatient — wait another roll and clear the point before offering the cube.

Further reading:

• Backgame Cubes by Dan Rovira, a video discussing certain backgame cube principles.

Next lesson: Doubling in closeout positions