Hi everyone. I consider myself I highly mediocre backgammon player. I mainly play against software so I don't really know how I'd do against a great player.

I've been playing Backgammon XG in competition mode with the computer on 'advanced' (highest level) for quite a while.

Over my last 96 games, the point total is computer 143 points, me 140 points- nearly even.

XG rates my Elo at 1762, overall rating is 'casual player' (intermediate checkers, beginner cube).

I guess my thought is this - how is it that the computer and I are so evenly matched on points if it's rating my play somewhat badly? Shouldn't 100 games be enough for the computer to show its brilliance? Is XG really just not that great? Or have I somehow unconsciously found some chinks in its armor by playing so much? (I know that it rates my doubling strategy bad, but the fact is, I feel like my doubling has helped a lot - I basically fold early when things are bad, and double early when things look good.)

Highest level of XG is XG Roller+ (++ if XG2), no? Regardless you're likely getting extremely lucky over this stretch.

Hi I am using XG on the iPhone - is XG2 available for that?

At what number of games would I then be able to say with some statistical significance that it's a truly even match (I have to admit my gut feel on high school statistics would say that 100 games should be enough to get to something beyond 95%, but I really have no idea).

Hi robo,

Confirm... you're not playing matches against the bot? Meaning, you're just playing single games against it, instead of a 5-point match, or a 7-point match, etc.?

If so, play some matches against it for a few weeks, and then report back your match results. (Report the number of matches you win vs, the number you lose... ignore individual games. Ideally, break it down. Report back the number of 3-point matches you win and lose, the number of 5-point matches you win and lose, etc.)

I'd be curious as to that result.

(Note that I'm not familiar with the phone app. I don't know if the strength and features are comparable with the PC app, but I would suspect they are not comparable.

Something that took me a while to spot was that I was much more likely to think, **** it, and close the game in a game where I was destined to lose. XG obviously doesn't get the benefit of the win in these cases.

As far as I know, unless your phone is ancient, the technology is sufficient to play at close to perfect.

I have both the phone version of XG (called XG Mobile) and the full desktop/laptop version.

The phone version is much weaker than the full version, so I wouldn't take any results you get against it too seriously. On the full version, 'casual player' is a range between intermediate and beginner, with error rates in the high teens. It may be the same on the Mobile version.

You won't learn much from playing XG Mobile because it makes so many mistakes. If you want to improve your game, switch to the full-featured version .

you're probably just running hot

it's not out of realm of possibility to be close in score vs a vastly superior opponent over a significant sample - I'm playing somewhere around 7.0-7.5 pr and one of my batches had something like 400-350 score in my favor and 2000+ elo

also, if you're using a hint function and changing your moves your errors are still reflected in pr but since you're now playing a much stronger game you'd be close in score even with a terrible pr

What about xg for a tablet?

I notice you wrote this in 2004. Has xg mobile improved since then?

I notice you wrote this in 2004. Has xg mobile improved since then?

I wrote this on April 23 of this year. You're looking at the date I first posted on the Forums.

Duh! So I was!

I didn't know the mobile version was so much weaker. On the 'settings' page of xg mobile, it states "xg mobile is a very strong opponent. Even on expert level, only the top players in the world can beat it". So they're being dishonest in making this statement?

'Dishonest' is perhaps a little strong. It all depends on your definition of 'top player'.

XG mobile on a highest setting plays with PR<0.5

I would really be surprised if expert was worse than 2.5, so Xavier is not at all far off with that statement

The Highest level in XG Mobile is "Champion". "Advanced" is playing much worse than that (PR around 8).

"Expert" level is player around 2 PR and will play fast even on a slow phone.

The Champion level is equivalent to XG Desktop 3-ply level so it plays at 0.45 PR

You can change the default opponent in the options (tap the XG icon in the bottom of the toolbar)

According to their website, "XG mobile champion plays at a PR of 0.55, while eXtreme Gammon 3-ply equivalent plays at PR 0.50". Is a difference of 0.05 really much weaker?

No, they're about the same.

I was playing XG mobile at what I thought was its highest level, but if what Xavier says is correct, I must have been playing at the Advanced level instead. My apologies. If XG mobile can play with a PR of 0.55, then it's a terrific practice opponent. I'll dust off my tablet and give it a workout over the next few days.

100 games is not enough! I've just had xg play itself for a 100 games, with both sides champion level. The final score? 134 - 94. A 40 point difference, despite the fact they're identical opponents!