How strong is that backgammon app? The big table

Update Sep 8,22: Backgammon KG added (PR 5.7 after 11 games)

Part of my app reviews is a solid test of the respective AI's playing strength. If the app supports it (and a good app should!) I play a couple of matches against it, export them to a file, and let Extreme Gammon 2 (PC) review our match on highest Roller++ level. This should give the reader a good understanding of the app's rating in "PR" (performance rating) points.

Apps that don't support export are harder to rate - I play something like a 3pt match on my iPad and transcribe it simultaneously into XG2, which is an exhausting process. Fortunately the apps that don't export are typically weak, so a rough rating is enough.

So, why not put them all together in a big table for you to compare? Here we go, (iOS) backgammon apps sorted from best to worst. 

 

 

 

Please note: this table is work in progress; I'll add new apps as time permits.

Please also note: it's difficult to rate the strongest apps; it might be unfair to rate a BGBlitz based app with XG2 only. I'm planning to compare the best 3 or so apps by analyzing a good number of matches with XG2, BGBlitz and GnuBG some day...

About the PR rating

PR ratings reflect how big an error on average you make per move, compared to the optimal move. The lower your PR, the better you're playing. XG uses the following names for the different PR ranges:

• 0,0 - 2,5 = World Champ 
  
• 2,5 - 5,0 = World Class  
  
• 5,0 - 7,5 = Expert 
• 7,5 - 12,5 = Advanced 
• 12,5 - 17,5 = Intermediate 
• 17,5 - 22,5 = Casual Player 
• 22,5 - 30,0 = Beginner 
• 30,0 and above = Distracted

The arguably strongest human backgammon player, Masayuki Mochizuki ("Mochy") has a PR of slightly above 2. Some sites call an average PR of less than 1.5 “superhuman”, which I’m also doing here.