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mike cook @mtrc
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I'll be livetweeting OpenAI's (first) bots-vs-humans DOTA 2 match at The International in this thread. I'll be keeping it light - will try and focus on big ideas and explain or avoid jargon.

📺 Livestream [will start soon!]: twitch.tv/dota2ti
🤫 Hashtag to mute: #OAI.
The game won't be starting just yet, but they should start the intro soon. We still don't know a lot about the match today. Big questions are: who's on the human team? How many matches are they playing today? And most important of all: have any more restrictions been lifted? #OAI
It's extremely hard to know what we'll see today. OpenAI have been training more than ever before in recent weeks, according to their project lead. They were already using a vast amount of compute to train, so this is incredible to hear: #OAI
While we wait, let's mention those restrictions. OpenAI doesn't play a full game of DOTA 2 just yet - some game systems are disabled, and some heroes aren't available to choose from. It's still an impressive achievement, but there's a way to go before we reach a full game. #OAI
But we might see some of those restrictions drop now - OpenAI said a few weeks ago they would work on more. I'm personally hoping we see even more heroes added, because watching the bots pick which heroes they want to play is one of my favourite parts of the game. #OAI
Alright, it sounds like the stream is about to switch over to the OpenAI stuff. Here's the link if you want to tune in: twitch.tv/dota2ti They're talking to Dendi right now, who played a 1v1 against OpenAI's first project last year. #OAI
A crucial thread throughout all of this is adaptation. Dendi seemed to have not seen the bot before, and was blown away by it. But what we heard last year, and this year too, is that teams and players who get many runs at this find ways to crack the AI open. #OAI
"At first you think, 'Eh, what can he do to me, I'm immortal!'... and then he starts to last hit [a crucial in-game skill] perfectly, block perfectly... then he's destroying you left and right." -- @DendiBoss on OpenAI's 1v1 bot. #OAI
Alright so OpenAI are facing off against eliminated pro teams, as some predicted. Their opponent today will be Pain Gaming - the only South American team at the tournament. Notable for being fast-paced and aggressive, which... might be a strength or a weakness, honestly. #OAI
The interesting bit about facing eliminated teams is that, in theory, their opponents get stronger each day. A very cool twist. I'm still wondering if it'll be a Bo3 or a Bo1 - I'm assuming for time reasons a Bo1 (?) which would be a huge advantage for the bots. #OAI
"The bots have fast reaction speeds and their calculations are perfect." - @MarchDota, an ex-pro, talking about how his team won a best of three in practice. "But I heard these bots got even stronger after playing against us, learning [what we] played against them." #OAI
Ok so it's a best of one each day. This is a huge advantage b/c some of these players probably haven't played against the bots before, and some may not have even seen replays. Most teams beating the bot report a 2-1 victory, losing the first game: #OAI
Okay, a huge deal: the OpenAI bots are now using a single courier. Couriers deliver items to players, and previously each bot had a personal immortal courier. Having a single one is how it works in the real game, and is a lot harder. It also undercuts the bots' key strategy. #OAI
The system has a 200ms reaction time cap, but it's important to realise that in that 200ms it reads the entire game state - things offscreen, things a human has to click to read. So human-comparable reaction time, but superhuman information processing #OAI
Okay, a really weird twist: there's no draft. The heroes were pre-selected by an expert player, and the two teams (OpenAI's engineers, and the human players) agreed it was a fair draft. That's a weird choice, possibly to save time? Because the bots were drafting earlier. #OAI
Alright we're in the game! So much going on, sorry. First blood (the first kill of the game, with an extra bonus reward) to the humans! #OAI
This early phase of DOTA is about resource gathering mostly. Players will hit the little monsters to get gold (which you buy items with) and XP (which you use to get stronger and upgrade skills). But OpenAI doesn't like doing this for long... get ready! #OAI
Honestly I don't want to underestimate OpenAI at this point, but incorporating all 118 heroes, with all the weird synergies and interplay that allows for, seems like too big a mountain to climb. But who knows! #OAI
"Every time it plays somebody good, it always wins Game 1." - that's one of the commentators, @blitz_dota there. I totally agree, if Pain haven't seen the bots before, they might get taken by surprise. But so far, so quiet! The humans even look... ahead? #OAI
One thing the bots continue to do is move around a lot. Normally 'support' heroes will move around to surprise heroes and kill them, but 'core' heroes often sit tight and gather resources. In this game, every bot has moved around at least once. #OAI
One of the human players there consumed by greed - sniper (the small guy with a gun and a cape) was almost safe there, but decided to turn around and fight. It's so tempting to play these risk gambles against humans, but the bots are 10x better at it. #OAI
Right now, the humans look a lot more comfortable than before. They've given away a few kills, but many of them were 'trades' (getting another kill in return). OpenAI looks less aggressive than it was before, honestly. #OAI
We did theorise this would happen after switching to a single courier. Couriers deliver items, and OpenAI used the five couriers to constantly ferry healing items to them. With a single courier, it's harder to keep everyone at full health. #OAI
Which isn't to say it's just that, of course - this is a pro team, more training has happened which might change their overall strategies, lots of factors involved. But the bots definitely feel different today. #OAI
A lot of DOTA 2 is about learning what heroes are, what they can do, and what items they need, so if this all looks like a confusing light show please don't worry - it looks like that to everyone at first! #OAI
Blitz talking about 'early aggression' here, as OpenAI destroy another tower (key buildings on the map)... but the humans have also taken two towers! Which is pretty impressive. Things feel fairly even right now. #OAI
But what we're seeing now is 'five-man' DOTA - the bots are grouping together and moving as one, which forces the human team to either face them as a team, or avoid fights altogether. You're seeing the results of that now - often bloody. This is what the bots do best. #OAI
One interesting thing: hear the crowd? You can't. Last year the crowd watching the 1v1 frequently went WILD but this year it's more muted. It's a lot harder to appreciate everything that's happening, and gameplay is a lot quieter than the flashy 1v1 showdown. Interesting. #OAI
Ok that was a beautiful teamfight by both teams. A lot of crucial spells used by humans and bots, but the bots come out on top, and for the first time they lead in terms of gold earned (which isn't a win condition, but can indicate who is winning). #OAI
The commentators are talking about how hard it is to ignore the bots. Against humans you might try to apply pressure somewhere else on a map, to draw the other team away from their plans, but the bots give you a much smaller window. Blink, and you've lost another tower. #OAI
Oof, not respecting the OpenAI Gyrocopter there. Gyro is the weird floating hero with wings, and one of the heroes the bot plays really well. w33 does manage to get the kill in return though! (w33 is playing Axe, the big red angry man). #OAI
Okay, OpenAI just 'got rosh', which means they killed a really big monster, and got an item that brings someone back from death. This is a side objective you can get to help you with a bigger objective - like pushing into the enemy's base! #OAI
As I believe I just heard @Blitz_DotA note, it feels like Pain don't entirely understand how aggressive OpenAI are yet. In the early game they were much quieter, but now it feels like the same old OpenAI again, and these bots punish mistakes. #OAI
"Getting rosh" "hand of midas" and "they're going for a smoke" are all terms that either mean nothing, or mean the exact opposite of what you think they mean outside of DOTA. #OAI
A nice exhibit there of how bots differ from humans: Gyrocopter, who has the second life from killing Rosh, is left to die by the bots because they know he can't be saved. Humans do something called "save your buddy" syndrome where people die trying to save others. Not bots. #OAI
And now a nice exhibit of the opposite: after Rosh dies it randomly respawns between six and eight minutes later. This is just something you learn, as a human, but is very hard for an RL system to learn so precisely. So the bots are checking to see if he's back. #OAI
That was a pivotal fight. It looked great for the humans initially, but you can see the moment the bots realise they can turn the fight - the big green guy uses a huge spell to stun everyone, and then his friends turn up. #OAI
If I'm not wrong, this is the latest I've seen the bots go (in a publicly broadcast match) without totally dominating the game. Exciting stuff! #OAI
Okay, the Lich (floating ice man) has taken Rosh's second life this time. Commentators laughing because this is not something you'd ever do, basically. But it almost makes sense here - his spells are vital, and the second life ensures he'll get to cast them before dying. #OAI
I just want to say, again, that a lot of tech organisations wouldn't have done a public showing without 100% guaranteeing a win. I am really happy that OpenAI are coming out here swinging, genuinely not knowing whether they're going to win or not. This is great stuff. #OAI
So as we enter the late game, we're going to see a common human strategy come out - give a lot of resources to one person until they become unstoppable. That's hfn's Sniper (old guy with cloak). But he can be killed easily. This is going to be tense. #OAI
Oh my god, some beautiful plays from @w33haa here - killing the courier, using a key item to block an attempt to root him in place, and then grabbing another hero and forcing them to fight him. That was some really beautiful stuff. #OAI
When you hear that CHUNK noise that sounds like metal on metal, that's Axe (big red guy) using his ultimate skill to instantly kill someone. It's been huge for the humans this game. Suddenly, an 8,000 gold lead for the humans! This game! #OAI
OpenAI beginning to do a few strange things as they come under pressure. Gyrocopter uses a disabling spell on a single tiny monster, Death Prophet (tall ghost lady) casts her most important spell without any enemies nearby. #OAI
I think Pain Gaming just broke this game wide open for the humans! #OAI
"Buyback" is a mechanic that lets you spend gold to instantly come back to life. It has a six minute cooldown, and you usually only use it in desperate times - gold is vital in this game. With two buybacks used for the bots, this leaves them a bit vulnerable. #OAI
The humans taking a superior trade here - OpenAI wanted to kill Rosh, so the humans attack their base. The bots decide they want Rosh more, so the humans destroy the first base buildings of the game! #OAI
Oh no 😅 one of the humans got carried away and ran into the enemy fountain - a special area in the base that kills enemies very quickly if they run into it. Oops. (A bot would never do such a thing, surely...) #OAI
43 minutes in. The humans have taken more objectives, and are ahead on gold. More importantly, the bots are doing a few weird things - using important spells for odd reasons. But honestly it's a nailbiter still. The bots are bad at the big decisions, but the small ones? Surgical.
We're also seeing a few things used incorrectly, including an item called a "Refresher Shard" which refreshes the cooldown on spells and items. This is an item rarely seen - it appears on the third death of Rosh. It's likely the bots don't have as much experience using it. #OAI
Wow! One of the humans scouted out the enemy team, revealed himself, and the bots instantly used two huge, valuable spells to kill him. This leaves them open for a bigger fight, and the humans pick up two kills in return. That was fascinating. #OAI
The bots had very poor vision of the area - most of the map is covered in a fog of war unless you or your allies can see it. Not having vision means you need to reason about where people *might* be, and that's a very complex proposition for reinforcement learning agents. #OAI
One interesting thing here is that the draft was agreed on by OpenAI's engineers, and the human players, but not the bots. To humans, these drafts look balanced, but thinking about how the bots like to play... I'm not sure if the bots would agree. #OAI
No time to think about that now - we're pushing the bot's base! Lots of objectives here - barracks, which... do something too complicated to tweet... and the Ancient, which is the final objective of the game! The pressure is mounting for the bots! #OAI
.@w33haa dies and instantly buys back - he can taste blood, he wants the win, but buying back can spell instant disaster if you die again! They're hitting barracks... jumping in... #OAI
A huge fight! Four bots are dead without buyback, and their Ancient is nearly exposed! I think this is it - I think the humans have done it! The humans have a little fun dancing around the last bot alive. #OAI
And it's done!

😊 Humans 1 : 0 OpenAI 🤖

Another game up tomorrow. So much to unpack. GGWP!
#OAI Snap thoughts:
🔹 The bots are a lot less aggressive than before. They feel worse than the previous exhibition, I think (but still, amazing).
🔹 The bots are still very good at moment-to-moment, but they seem bad at macro-level decisions. I have more to say on this!
🔹 The bots will continue to learn and be updated today. I'm not sure what that means - I hope not too much human nudging?
🔹 Holy shit, a team of bots played a 45 minute game against a pro-level team on stage at The International.
🔹 Will try to write something tomorrow!
#OAI
One last footnote: @paiNGamingBR are 4/5 Brazilian, and South America is a region that is looked down on and undersupported in the DOTA 2 community. Huge props to them for coming out, being so entertaining, kicking butt and ultimately winning. #dota2ti 🇧🇷
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