Two things stand out to me, and they have nothing to do with micro:

The AI consistently did a 'deathball push' strategy, where small early advantages snowball and they pushed hard to exploit that early advantage. One of the things that enabled that was that resources were more evenly spread across the team, allowing the heroes that were strong earlier to do something with that advantage. Competitive and casual ranked play hasn't switch to always do deathball, but there is a marked increase in the amount of resources that early-timing 'support' heroes take, they are a lot greedier than before OpenAI. (as pointed out by a sibling post) It's unclear if that is either because of lessons from OpenAI-five, or because of the balance changes (there is more resources to be had around the map these days).

The second thing that stands out is that the 1v1 OpenAI and the 5v5 OpenAI did buy a lot more of 'consumable' items, mana and HP potions basically. These were considered too inefficient before, people tended to prefer items that gave a more over-time regeneration and long-term efficiency. What the bots did was /constantly/ ship consumables over, which was kind of surprising at the time. It used that consumable resource to either force an opponent away from xp/gold resources (lane, jungle) or allow it to stay after aggression. Once pros started buying a lot more consumables, casual players quickly followed suit.

Sort of, but I can't be sure that this attributed entirely to OpenAI or other changes. It used to be more common 5-6 years ago to devote all available resources to one player ("carry") and the other 4 make space for the carry. In the last few years it's become more common to have 3 cores who get sufficient resources. It also sometimes happens that the 4th player has resources equal to the top 3. But always, the 5th player is dirt poor.

FWIW the developer of the game has also tried to fix this over the years, devising ways to get more resources to the 4th and 5th players. For example, there is a system similar to UBI where all members of the team benefit equally from "bounty runes". But till date, the bots have achieved a level of egalitarianism yet to be matched by human players.

> FWIW the developer of the game has also tried to fix this over the years, devising ways to get more resources to the 4th and 5th players. For example, there is a system similar to UBI where all members of the team benefit equally from "bounty runes". But till date, the bots have achieved a level of egalitarianism yet to be matched by human players.

this kinda makes sense. I'm more of a cs player, so hopefully my observations aren't totally off base. generally, a group of five humans will have some sense of who their best player is, who their worst player is, and who's good at specific roles. for instance, you might deliberately send your worst player into a bombsite first to gain info about the opponent's defense (and save your best player to react to that info). or you might send the person who's best at "entry fragging".

an egalitarian playstyle doesn't make sense when you have human players with different capabilities. you want to play to each person's strengths. if you have an algorithm controlling five heroes (or five instances of the same algorithm, idk how it works), there's no "best player" to send more resources to or dedicate to a specific role. I don't know enough about moba to say whether this is even an advantage.

none of this stuff is particularly interesting in counterstrike. a circa 1999 aimbot with a good ping will beat any human player.

Replace player by character and you're basically there. Typical about MOBA's (and now also in e.g. Valorant these days) is that each character you choose comes with a certain 'kit' of skills and stats that give it different strength and weaknesses. A character might have powerful spells early on, others are very weak early but dominate towards the end because scale really well with extra resoures. The former will typically act in a more sacrificial role to enable the latter. The OpenAI favored a strategy where you snowball an early advantage into an early to midgame win, before the 'carry' characters start to dominate. That in itself is not new though, it just executed it in a weird but consistent way. One of the weird ways was indeed that 'egalitarian' way of having the 'support' characters be more greedy, enabling them to have a higher impact on the early/mid game timing, when the deathball starts rolling.

The Shadow Fiend AI was consistently beating pros in 1v1 because it had flawless technical execution of the standard gameplay on that hero, eventually forcing errors out of the fallible and emotional human players. It wasn't anything new, it was just perfect.

They've moved beyond that now. Shadow Fiend won mostly due to superior micro but their newer 5v5 bot has human-level "planning" and executive function.