Zare Race Database packs a lot of information into a small window.

Use the sliders to set up a position. Set the number of rolls for your opponent.

ZRD has an unusual interface for setting up positions. Use the vertical sliders to set the number of checkers on each point, and choose a number of rolls for your opponent. The above position has 5 checkers on the 6-point, 4 checkers on the 5-point, 3 checkers on the 4-point, 2 checkers on the 3-point, and 1 checker on the deuce point.

There is no “Evaluate” button. As you set up positions, ZRD immediately evaluates them.

The pip count and wastage are usually the most important statistics in a race.

Usually, expert backgammon players calculate the pip count in a race, but this doesn’t tell the whole story. The most important adjustment is the wastage which you can learn to estimate accurately using a program like ZRD. The sum of the pip count and the wastage is the effective pip count (epc). The epc lets you compare efficient positions (which have a wastage of about 7) with rolls positions like the 5-roll position above. A 5-roll position is similar to an efficient position with the same effective pip count of 36.

In the above screenshot, I unchecked “Rounded.” This shows more precision than most people need. A pure n-roll position has an effective pip count close to 7n+1, and the epc of a 5-roll position is about 36.0001.

Cubeful equites vs. 3-roll position

ZRD reports the chance to win and the cubeful equities with each cube location and with each player on roll. A “P” indicates that the correct cube action is double/pass or redouble/pass. A “T” indicates the correct cube action is double/take or redouble/take. When you have a chance to double, ZRD reports the equity from not doubling. For example, if you are on roll with checkers on the 6, 5, and 4 against a pure 3-roll position, and the cube is centered, ZRD reports “P 0.818.” This means you should double, your opponent should pass (giving you 1 point). If you fail to double, you only get 0.818 instead of 1 point. If you double and your opponent takes, you average 1.27 points.

If your opponent with the 3-roll position were on roll, then you would win 36.259% of the time and would have an easy take. It would still be correct for your opponent to double or redouble.

Registered version. The best way to play this 1-1 is not to minimize the effective pip count.

In the trial version of ZRD, you can see which play minimizes the effective pip count. In the registered version, you can optimize cubeful equity, or try to save the gammon efficiently. To minimize the effective pip count, you would play 1-1 4/off which is the most efficient by a significant amount. However, the best play against a pure 6-roll position is 6/4 5/3. This is the best play in any cube location and for maximizing your winning chances. In the screenshot above, you can see that 6/4 5/3 wins about 0.4% more than 4/off against a pure 6-roll position.

Interested? Try ZRD for free.