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Arimaa >> Site Discussion >> Bot Ladder concept
(Message started by: NIC1138 on Apr 3rd, 2006, 1:44am)

Title: Bot Ladder concept
Post by NIC1138 on Apr 3rd, 2006, 1:44am
What's the concept behind the Bot Ladder?  Isn't it to sort all the bots by rating, and putting the bots below my rating in the right, and the ones above in the left, with the "play"  link by the side of the bot with the rating just above mine?...

right now there's a bot above me, " bot_Loc2005P1 1277 Play ", and on below me, "bot_Loc2006P1 1312 Play"...  ??? But the rest is just fine...

Title: Re: Bot Ladder concept
Post by Ryan_Cable on Apr 3rd, 2006, 2:39am
Bots below you are bots that you have beaten at least once.  Bots above you are bots at your level that you have not yet beaten.  To advance to the next level you must beat every bot above you at least once.

Title: Re: Bot Ladder concept
Post by NIC1138 on Apr 3rd, 2006, 10:45am
So it has nothing to do with the ratings?  But how dos it happens that somtimes I won from a bot and climbed two places in the list?...

Title: Re: Bot Ladder concept
Post by Fritzlein on Apr 3rd, 2006, 1:17pm
Do you mean that you got ahead of some bot in the ladder without ever beating it?  That's weird; it never happened to me.  Which bot did you pass without beating?

Within each level the bots are presented to you in order of their rating, but usually the best bot on level N is higher-rated than the worst bot on level N+1, so overall you don't quite get the bots in order of their rating.

Furthermore, after you beat a bot and get past it on the ladder, someone else might lose repeatedly to that bot and push its rating up higher than the rating of the bot you are supposed to face next.   No matter how high a bot's rating goes, you stay ahead of it on the ladder as long as you have beaten it at least once.  Conversely, no matter how low the rating of some bot gets driven down, you stay below that bot on the ladder until you beat it.

Clear as mud, right?  But the ladder is a lot of fun, IMHO.

Title: Re: Bot Ladder concept
Post by NIC1138 on Apr 4th, 2006, 11:37pm
I don't remember anymore, I think is wasthe two "P1 P2"  robots.  what does that mean anyway?? Are they just a single robot?

Now what's the "level"  is it's not the rating? Have you just defined the order and left it like that?...

And also about the new players  losing: i've heard about bots constantly playing against each other...  doesn't that quickly  minorate the effect of the human defeats in the low levels?....

Title: Re: Bot Ladder concept
Post by Swynndla on Apr 5th, 2006, 2:18am

on 04/04/06 at 23:37:32, NIC1138 wrote:
I don't remember anymore, I think is wasthe two "P1 P2"  robots.  what does that mean anyway?? Are they just a single robot?

Yea ... botA-P1 and botA-P2 are the same bot.

Now lets see if I can remember ... P1 = ply 1 and P2 = ply 2 ... ie how many moves they look ahead ... these bots are tied down to only look ahead by that amount.  I think that one "ply" means one side having a turn, while one "move" means both sides having a turn (am I right? ... if so then 2 ply = 1 move).


Quote:
Now what's the "level"  is it's not the rating? Have you just defined the order and left it like that?...

Yup.
Grouped ... each level is harder in that the ply goes up, or the time per move goes down.  The good bots aren't in the lower groups.  I love the bot ladder ... I always play bots at my level or a bit harder - it's great :)


Quote:
And also about the new players  losing: i've heard about bots constantly playing against each other...  doesn't that quickly  minorate the effect of the human defeats in the low levels?....

I think they quickly sort themselves out, and any rating points are spread.  Fritzlein talked about this in a post ... I think it was:
http://arimaa.com/arimaa/forum/cgi/YaBB.cgi?board=talk;action=display;num=1065901453;start=105#105

Title: Re: Bot Ladder concept
Post by Fritzlein on Apr 5th, 2006, 3:35pm

on 04/04/06 at 23:37:32, NIC1138 wrote:
I don't remember anymore, I think is wasthe two "P1 P2"  robots.  what does that mean anyway?? Are they just a single robot?

Swynndla is right, two bots with the same name except for the P1 and P2 extension use exactly the same evaluation function.  The only difference is search depth.

P1 and P2 do indeed stand for 1 ply and 2 ply, but that's a little confusing.  For some programmers a 2-ply search means looking ahead two steps, but for others (including Omar, who names the bots) a 2-ply search means looking ahead eight steps.


Quote:
Now what's the "level"  is it's not the rating? Have you just defined the order and left it like that?...

Yes.  Omar just defined the levels totally independently of ratings.  It is somewhat silly that all the bots which take 2 minutes per move are on a higher level than all the bots which take 15 seconds per move, because the blitz bots are actually much harder to beat.  I think Omar put the slow bots on the last level, not because they are toughest to beat, but because they are boring, and he wanted folks to have fun with the low levels of the ladder first.


Quote:
And also about the new players  losing: i've heard about bots constantly playing against each other...  doesn't that quickly  minorate the effect of the human defeats in the low levels?....

One purpose of the random bot vs. bot games was to make the bots more accurately rated relative to each other.  Before the BvB games started, the good bots were rated too low and the bad bots were rated too high.  Now that bots are passing more points between each other, the scale has spread out as intended.

On the other hand, the worst bots are still clearly overrated.  Probably ArimaaScoreP1 and ArimaaScoreP2 belong at the bottom of the ladder, even though they are rated eighth-worst and fourth-worst respectively.  I don't think it is possible there are seven bots worse than ArimaaScoreP1, but it has too high a rating due to victories against total noobs.

Title: Re: Bot Ladder concept
Post by 99of9 on Apr 5th, 2006, 8:02pm

on 04/05/06 at 15:35:24, Fritzlein wrote:
P1 and P2 do indeed stand for 1 ply and 2 ply, but that's a little confusing.  For some programmers a 2-ply search means looking ahead two steps, but for others (including Omar, who names the bots) a 2-ply search means looking ahead eight steps.

Omar is going by the strictly correct definition of "ply".  The reason many of us use the number of steps is to be able to clearly distinguish between e.g. a bot that searches 6 steps deep and one that searches 7 steps deep.

Title: Re: Bot Ladder concept
Post by omar on Apr 9th, 2006, 8:29am

on 04/05/06 at 15:35:24, Fritzlein wrote:
I think Omar put the slow bots on the last level, not because they are toughest to beat, but because they are boring, and he wanted folks to have fun with the low levels of the ladder first.


Exactly. Because the slow bots take a long time to finish the
game, players might get bored and stop playing at that level and never encounter the fun and seeming harder (at least for humans) Fast and Blitz bots.




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