There has been some discussion about trying to put Ais into the ladder queue. I would like to make this a proper discussion. Personally I would be interested to see how ais would actually perform in ladder, aka which rating they would converge to. So the question which ai is the best competitive player could finally be answered! This would probably not disturb the lower ladder regime too much as each Ai would only need to play 30 games or so to have it's rating converge.
A more interesting role of AI in ladder would be to have new players play their placement games against AI. I want to present a concept and go into some benefits and problems.
Ais would first play ladder games until their rating converges. New players would face these Ais in their first placement matches. Which AI they face could be determined by the AIs they beat in the previous placement matches to create a less frustrating experience. The rating of the Ai would not be affected by placement matches to prevent the biass from mostly facing new people shift the AIs rating. It would instead play some games against converged players in ladder to readjust it's rating to possible skill/ meta changes.
So why would we even want to do it?
It would prevent new players facing ~1300 rated players in their first matches and vice versa saving 1300 rated players from having to beating up noobs (This was quite frustrating when I was 1300). I don't have any data of how many noobs and players you face at that rating range but it is quite significant. I found out that there are about as many people who played one ladder game as who played more than one ladder game in the data from 2014 to 2020. So there were a lot of players who clicked the ladder button, got absolutely wiped and then never clicked it again.
Edit: Apparently fixed, new players get focre matched with people with lower rating. Getting a more accurate starter rating might still be desireable, as it causes less unbalanced matches.
The reasons I see against it:
Players might not want to play against AI in ladder but people would possibly prefer to face an AI over getting wiped by 1300s during placement. The games the AI would have to play in ladder to readjust its rating are probably neglible as I would expect it to be less than one per week. The initial games to get the AIs rating might cause some upset though.
I'm not even sure if it would give the result we are hoping for: For instance the AI might be too weak to be a meaningful opponent. If the AI constantly looses to new players the system won't adjust the players rating by a lot. µ and sigma only get adjusted marginally when a higher rated player wins against a lower rated one.
(http://www.moserware.com/assets/computing-your-skill/The Math Behind TrueSkill.pdf, page 29 onwards)
So extra information of the skill of a new player we get by having him face a weak AI is very small and he would have to face 1300s after his placement matches anyway.
The fact that we are changing which rating new players face in their first matches might also change the mean of the whole rating distribution. But I'm not certain on that. Fact is that trueskill has a rating deflation over time. It is observable in the distribution of ladder µ over the last couple of years, but appears to be stabilizing. Avrg.rating should be mean. µ of all players that played at least one ladder game in the previous year and had a sigma<100:
In summary I think having players face AIs during their placement matches is a good Idea, given we have an AI that can actually beat the average ladder first timer. The other approach would be to manually match these players against weaker opponents. This is probably fine for new players but it made TMM quite a nightmare after the reset as non converged strong players were matched against converged noobs.