Even the base example would make that specific scenario trivial: an account that is new has no business "being better" than everyone else.
The only group you'd punish with that is skilled players that lose their account (and create a new one), but if you use a moving skill window they can grow back into their plausibility pretty quickly, and it's a small cost compared to everything else. And you could even mitigate that by making things like the first 10 matches require a different plausibility score than the matches after that.
And with different I don't mean "no scoring at all" or something like that. But a cheater tends to not cheat "a little bit". You might have togglers, but that sticks out like a sore thumb (people don't suddenly lose or gain skill like that). And even if that fails (lots of "cheating a little bit" for example), you've still managed to boot out the obvious persistent cheating.
And that's just with 1 example and 1 scenario. Granted, that bypasses the fact that it is still difficult and doing it broader than one example/scenario is even more difficult, but that's why I ended the previous comment pointing out the difficulty and associated cost, which goes hand in hand with the balancing difficulty you pointed out. Even tribunal-assisted methods (not sure if Riot games still does that) have the same problem.
What about new players who are competitive in other, similar titles, and thus start off with a strong advantage?
And - what about experienced players who cheat?
In some scenes, it's actually more often that cheaters are some of the best, most experienced players who have a strong competitive lean and feel they 'deserve' to win, so use cheats to get an edge. It's far more common than you'd think.
That's the problem with any anti-cheat system. It's all the what-ifs. Every single 'clever idea' that has been theorized under the sun has been tried and most have failed.
Those players would be initially quarantined either way and a sliding experience window would put a limit on what is plausible. Same goes for transferrable skills.
Experienced players who cheat will still be subject to plausibility. Say there is a normal amount of variance in humans but suddenly some player no longer has variance in their action. That's not plausible at all. Or a player looking at things they cannot see, that might sometimes be a coincidence, but that level of coincidence is not plausible to suddenly change a drastic amount.
Again, this sort of thing doesn't catch all subtle cheaters, but those are also not the biggest issue. It's the generic "runs into a room, beats everyone within 10ms", and "cannot see, but hits anyway all the time" type of cheat you'd want to capture automatically.
A what-if in a tournament or the top 1% of players is such a small set of players, you'd be able to do human observation. Even then someone could cheat, but you're so far outside of the realm of general cheating, I wonder if that's worth including in a system that's mostly beneficial inside the mass market gaming players.
Either way, this sort of detection is usually done in the financial and retail world, and results in highly acceptable rates and results. It's not perfect with a 100% success rate or something like that, but it's pretty successful. Just not something studios or publishers seem to want to invest in. It's much simpler to just buy or licence something (like Easy Anti-Cheat). Broad internal expertise isn't something the markets are rewarding at this point.
> Even the base example would make that specific scenario trivial: an account that is new has no business "being better" than everyone else.
You cannot and should not rely on that, depending on what account really means, e.g. in ioquake3 games, having a new GUID (you delete a specific file to get a new one) makes you a new player.
Sure, it would only work on games where the client and server both authenticate, otherwise none of this will work as there would be no reputation to be relied on.
I've even seen the weird combination of the client and server both authenticating, but the account owner being given a choice if they want to 'level up'. It essentially means your public reputation and match history (and actual experience) no longer align.
I suppose that matters less if we're doing checks on the actual data, but for the player base, you cannot rely on what the game reports about the experience of your opponent, which makes for very confusing matchups (and the accusations that go with it).
The only group you'd punish with that is skilled players that lose their account (and create a new one), but if you use a moving skill window they can grow back into their plausibility pretty quickly, and it's a small cost compared to everything else. And you could even mitigate that by making things like the first 10 matches require a different plausibility score than the matches after that.
And with different I don't mean "no scoring at all" or something like that. But a cheater tends to not cheat "a little bit". You might have togglers, but that sticks out like a sore thumb (people don't suddenly lose or gain skill like that). And even if that fails (lots of "cheating a little bit" for example), you've still managed to boot out the obvious persistent cheating.
And that's just with 1 example and 1 scenario. Granted, that bypasses the fact that it is still difficult and doing it broader than one example/scenario is even more difficult, but that's why I ended the previous comment pointing out the difficulty and associated cost, which goes hand in hand with the balancing difficulty you pointed out. Even tribunal-assisted methods (not sure if Riot games still does that) have the same problem.