Stats: Your backgammon performance on one page

Today I've released a new version of BackgammonDB with Stats, an overview of your performance across all matches in your database on one page. It lets you see how your performance rating changes over time, how well you do at different match lengths and where you make your errors.

Think of it like the XG "Profile" page but better. It looks prettier, but it also includes a lot more information that wasn't possible to extract before.

Also in this release: Increased (and customizable) font sizes, checker color customization, improved tagging and bug fixes.

Read on to learn more!

What's on the Stats page

Performance over time

The top graph of the stats page is your performance rating over time. This shows a moving average, to give a better impression of whether you are improving without match-by-match noise.

Below, you can see that my checker play is pretty flat around 10 PR, but at least my cube play is going up! (from intermediate into advanced).

You can customize this graph by overall, checker or cube PR, change the window for moving average, view by matches or decisions. You can also switch away from moving average and view by week or month instead.

Here's my checker, cube and overall play by month.

Segmented Performance

There are a couple of different things going on in the next section. Top right is pretty obvious -- just a chart of your win/loss stats across the database. The other three show your performance and errors by segment.

Top left is your PR based on match length. Useful to see how well you perform in different game types (mine is a bit boring as I almost exclusively play 9pt matches in XG). Bottom left is a histogram of how many matches you've played at each PR level. It should give you an idea of how consistent you are (here you can see I'm overwhelmingly playing Advanced, with intermediate more common than expert, and I have a few match howlers pulling me down).

Bottom right shows the total equity loss by error category. Are you losing equity mostly in lots of small decisions, or is it the blunders and howlers that are really pulling you back? (I'm very much in the latter category. Over a third of my equity loss comes from a few howlers).

Cube performance

This is where things get interesting. Because BGDB has the entire match results in your database, we can go a lot further than this simple sort of segmentation. The first one we've built is a breakdown of your cube decisions.

This shows equity loss when deciding whether to double (on the left) and, when facing a cube, whether to take or pass. It then breaks this down into whether analysis thinks it was right to see how often mistakes are being made.

So on the left, it shows that I slightly lean towards too aggressive with the cube: I have lost more equity doubling, when it was too early, than I have missing a double. But interestingly, of all the times when it was correct to double, I missed it over half the time.

On the right, you can see that I definitely take more than I should. I've lost more equity here than when I incorrectly drop. Of all the times when passing was correct, I actually took it almost half the time.

Moving forward, there's a lot more scope to present data like this. How much equity is lost during back games, and is that an area you should focus on? How much equity do you lose in race positions vs holding games? This is definitely an area I'd like to look at more in the future.

Other changes this release

Customize checker color and font size

You can now select from a palette of six different colors for each theme, and can swap colors over if you'd prefer.

I've also changed the general text size. By default, the text size across the whole app has been bumped up by one step to make it more legible on smaller screens and tablets. If you prefer the original condensed look, there's a setting for "smaller," and there's an even larger size available too.

You'll find both settings in the settings drawer in the match or position viewer.

Improved displays when you have a lot of tags

The UI wasn't really built for lots of tags, which users reported to me. So I've changed the tag box to be an auto-complete, capped the number of rows for tag suggestions, and tidied up the display of tags in filters.

Bug fixes

Finally, some bug fixes:

• Cube "optional double" detection. A bit of floating-point noise could make a doubled cash look like a real decision and quietly inflate your PR higher than what XG reports. The guard is now widened and pinned to verified bounds; affected matches correct themselves automatically on import.
• Better handling for unanalyzed positions. A bit of housekeeping.
• Better position error handling. Corrected some issues around error bands being changed and not reflected in your saved positions.
• No forced database migration on the homepage. It will now only trigger when you actually go into the app.

Still to come in the next release: saving GNU Backgammon analysis for matches you imported without it, and .mat file import.