Backgames

The last game plan we will discuss is called a backgame.

….I don’t know where to start with these. They occur only 5% of the time, and are super challenging because their play is antithetical to typical forward-backgammon play.

A backgame is like an extreme holding game. In a backgame, you’ve fallen so far behind in the race that there’s no reasonable expectation of catching up by rolling well, and you are 100% dependent on landing a hit and trapping one of your opponent’s checkers behind a strong prime. Whereas in a holding game, you might be trailing by 15 – 30 pips, in a backgame, you could trail by over 100 pips. A deficit this large means you likely have 5 or 6 checkers back. Here’s what a backgame might look like:

This situation looks hopeless, but actually, you still have decent winning chances, something like 45%. This is thanks to those 2 anchors in your opponent’s homeboard, which nearly guarantee you a double shot at some point. That’s much better than a typical holding game, where you’re hovering around 23% win chances. Oddly, by trailing further in the race (here, to over 90 pips!), you’ve increased your equity in the game. Below is a chart Mochy loves to share when discussing backgames:

On the left of the chart, we are leading in the race, and so have positive equity (we’re winning!) As the pip count crosses zero and we start trailing, our equity decreases and goes negative (therefore, we’re losing). However, at some point, the more we trail in the race, we start losing less and less, until eventually we’ve almost broken even again, meaning it becomes better to commit to a backgame than to try to catch up in the race. This means you need to try to be hit to improve your win chances. (I told you backgames were antithetical to forward games!)

There are a few catches, of course. First, many of your losses will be gammons, which would not be the case in a holding game. In the position above, you have over 35% of a chance to lose by at least a gammon, which is almost equal to your raw winning chance! Second, getting the right amount of timing (that is, being sufficiently behind in the race) is very challenging. Sooner or later, you can no longer fool your opponent into keeping hitting you, and it becomes very easy to accidentally crunch your homeboard, with all of your checkers lined up on the ace and deuce points. Any unwelcome 66s or 55s rolled can be gamebreakers.

Still, the purpose of this article is mostly to point out that things are not hopeless once you start to seriously trail in a game. You just need to anchor up twice and build a pure prime in your homeboard.

But how could we possibly win so often from this position where we’re trailing so far in the race? It’s worth playing the position above out for a few shakes to see what often ends up happening:

Here is a typical position that is reached from the original one above. Earlier, we were trailing by 90 pips, and here it’s only 85, so both sides have rolled average numbers to end up here. We never landed a shot, and Gary is about to bear in his final checkers, yet we are still estimated to have over 40% win chances!

Gary actually finds himself in a precarious position! He leaves a double shot when rolling a 65 or 54 (4 rolls). Note that because of the huge pip count lag, we’ve managed to preserve a threatening prime and are likely to win if we hit. If we miss, we’ll probably get another kick at the can soon. For example, after stripping the 6-pt, Gary will also have bad 43, 55, 33 (4 more rolls). Bearing in and off against a well-timed backgame is a minefield.

This exercise also reveals why it’s hard to play backgames properly. In addition to happening infrequently (meaning you don’t have many opportunities to practice them in the wild), the consequences of any decisions are only felt way after they’re made.

The last point worth mentioning about backgames is that they are famously modelled very poorly by analysis software. This means that they are relatively challenging to study. You will find that many backgammon books will highlight tons of corrections in the chapters on backgames, making them almost unreadable. There are also very few books on the topic for this very reason.

That said, they’re crazy fun to play. It’s like the wild west.

Further reading:

• A seminar by Mochy on how to play backgames (where I found the figure above)
• A video of a championship game between two top players, Sander Lylloff and Zdenek Ziska, which devolves into an insane-looking one-of-a-kind backgame.

Next lesson: Intermediate checker play