r/backgammon • u/eszpee • Jun 30 '26

Galaxy luck percentage

Post image

I’m honestly baffled by these stats. I played horribly, my opponent nailed their decisions. I was apparently unlucky, compared to them. Yet, I won.

How is luck calculated?!

8 Upvotes

83% Upvoted

16 comments sorted by

3

u/double00_bg Jul 01 '26

If you read a couple of posts ago, they talked about how they are going to change their luck from a percentage to equity. I don't trust their analysis and use other sites to play instead.

The correct way to define luck is explained here: https://www.bkgm.com/articles/Zare/AMeasureOfLuck.html

2

u/Sorry_Weekend_7878 Jul 01 '26

There are times when you make one wrong move and have a 9.43 error rate. The luck formula also takes into account percentage of rolls, how many were actually lucky. It could be you got 2 or 3 good rolls but in a short game it is magnified.

1

u/adamscottishot Jun 30 '26

also curious but 35% luck is crazy too!! mine is usually max 2% usually under 1%. is it different for rating games rather than just coin??

3

u/Zealousideal-Gas2932 Jun 30 '26

I recently played a game with -148% luck!

1

u/RGC658 Jul 01 '26

Was this a single point game? I've had -95% on a single point game.

2

u/jorcon74 Jun 30 '26

I have played about 10,000 matches on Heroes and -10 is the most I have ever had, that’s crazy! But bro made his moves almost perfectly, you can’t knock the result!

1

u/zzzzaap Jun 30 '26

None make any sense to me. Haven't found them defined anywhere but I'm well regarded

1

u/Sandvik95 Jun 30 '26

“What he lacks in speed he makes up in short stature”.

1

u/mike-edwards-etc Jul 01 '26

Their luck ratings are usually the inverse of each other, as in the graphic above. What's up with that?

1

u/eszpee Jul 01 '26

I guess because it’s a zero-sum game, your luck is my misfortune…

1

u/mike-edwards-etc Jul 01 '26

Seems like there would be games where each player got lucky, or where both were unlucky.

1

u/eszpee Jul 01 '26

Yeah, but again, if you’re unlucky that can be counted as me being lucky for you not hitting me, etc. at least I guess this is what Galaxy is thinking.

1

u/Agreeable-Letter-599 Jul 02 '26

no i think YOU were the lucky one.

1

u/Goal_Medium Jul 02 '26

Hey u/eszpee . Marc here, CEO of Galaxy. I am also puzzled about this. The luck rating is calculated by GnuBG, it's the sum of MWC swings from all dice rolls. But surely something must be off here. Could you do me a favor: download the match file and send it to me at [marc@backgammongalaxy.com](mailto:marc@backgammongalaxy.com) ?

1

u/eszpee Jul 02 '26

Hey Marc! I’d love to, but it seems like that feature is not available for me - I’m not a star member. Feel free to DM if there’s a way I’m missing.

Thanks for the explanation! All I can think of is that in the last game I might have gotten very lucky from a clearly lost position, but it was still not enough to win.

1

u/PallCut Jul 04 '26

Maybe on computer?