1. terrible at warding and dewarding
2. are terrible at using spell spam to farm. while their aoe
spell usage is great in team fights, they suck at using spells to farm when they are alone. Gyro used his ult to farm a normal sized lane and still missed half the creeps.
3. don't understand bouncing spells like the lich nuke. In fact many times lich used that spell as a poking spell.
4. Bad at non-nuky/long running ultimates. DP made really bad usage of her ult several times outside of team fights.
5. Bad at judging Roshan respawn.
6. bad at using ability runes.
7. Are bad at juking. They have the right idea to start the juke when the chasing enemy is on a high ground ramp, but they can't time the highground fog jukes properly.
8. not good at prioritizing specific heroes in team fights (cores over supports, if both look equally chasable)
9. terrible at dealing with split pushes. They prioritize defending their towers over everything. Also bad at split pushing, in general.
10. bad at properly utilizing buybacks. If some heroes buyback during the defense, it is expected that the remaining heroes should ensure that the enemies can't escape, otherwise buybacks would be pretty useless.
11. when they are behind, they simply don't have any coherent way of catching up other than taking huge team fights. Which the enemy team will deny the AI, if they are smart.
For now winning lanes and having overwhelming team fighting abilities is the only meta that the AI seems to be doing.
Is OpenAI's team-fight "so good" that compensates for these huge mistakes and allows them to compete with pro teams?
For me as a player, the team fights are quite confusing and overwhelming. The most complex part of the game.
If the OpenAI team got the teamfights covered that well, I'm pretty much sure they can improve their farming/warding techniques as well.
I don't know if the OpenAI supports can play the warding mind-games, which also for me personally involve 1000+ games' experience. I see interesting wards from teammates occasionally and file them away in the memory bank. Especially "hipster wards", I like to call them, just wards that "see" the opponents but are not in the highest-probability spots like on pedestals or on ramp edges. Just throw an obs ward near a couple medium camps, for instance, and you can really gain some important intel w/o a sentry ruining your ward. Can the OpenAI team learn to do this sort of behavior?
This is the core of what I want from open ai and feel like I'm not seeing. I want the AI to _reason_ that blocking the creepwave brings the equilibrium back to your tower and results in an easier lane. Not just to say "this thing works so I'll do it a lot" - but to say "if I do this then it will have this impact on the game state".
What we got was the devs specifically training models for goals like creep blocking. Which, you know, just seems a bit meh
edit: i would also expect that the robots are deny nazis, who severely crimp the farming of anyone who opposes them in the lane.
- 5 invulnerable couriers per team allow for very constant poking and pushing styles as regeneration items can be ferried back and forth from the base. This favours team fighting deathball oriented strategies where you just have non-stop aggression.
- Very limited hero pool, this further compounds on the earlier issue as many good deathball team fighting heroes are on the available pool but some very common counters to this strategy are not.
Also, humans lack experience in this version of the modified "metagame" or they would likely be able to adapt. This is IMO the biggest hurdle for humans, they haven't really played this version of the game and they probably weren't exactly expecting it, the AI has trained over many "computational years", the humans have a couple of games to catch up.
1. May be an unimportant waste of time and money given some unknown superior strategy.
2/3/10. May be similar to Alpha Go/Alpha Zero. A win by 1% is still a win.
11. Is a known issue.
This is AI, so what OpenAI needs to improve on, if anything, may be the ability to tell this stuff directly to the AI so it could skip hours of play.
Also, maybe our view is too limited and the AI actually learns even better strategies from competitive self-play. Strategies our human way of improving would miss.
This is generally a good point, but in this specific case we can see that no such strategies showed up. The bots did terrible, obviously bad things (like stacking wards in bad places on top of each other or having a weak support hero take the aegis). More importantly, they didn't win.
Incidentally, this is pretty much what Kasparov did when playing Deep Blue, with some success: https://en.wikipedia.org/wiki/Deep_Blue_versus_Garry_Kasparo...
Aside: As a non-Dota-playing HNer, the only one of those points I found comprehensible was #11. Gaming jargon can be pretty impenetrable to the uninitiated...
- 5 vs 5 heroes over 3 lanes and a jungle
- destroy the enemy team's towers in order push towards the enemy's Ancient (base) and destroy it
> warding and dewarding
wards serve to create visibility (over the fog of war)
2 types of wards: one for general visibility, and one to detect invisible heroes (but has no visiblity over FOW)
> spell spam to farm
having a hero use multiple spells to rapidly kill a bunch of Creeps sitting somewhere in the jungle
> bouncing spells like the lich nuke
- poke spells target and damage a single enemy hero
- bouncing spells target one enemy hero but can jump to nearby enemy heroes as well
> Roshan respawn
Roshan is a large creep in the jungle. It drops a precious item that resurrects heroes when they die.
> ability runes
Runes are temporary enhancers (movement speed, attack damage, ..) found in the jungle
> bad at juking
when one tries to play mind games with the enemy
when a player's hero dies they're allowed to pay a fee to revive their hero instead of waiting (can only be used once)
For the jargon, the Liquipedia glossary might be helpful: https://liquipedia.net/dota2/Glossary
Dota is a 5v5 game where each player controls a single hero unit. The playing field has three paths that connect the opposing bases, and an endless source of dumb computer-controlled units march along these paths to try to destroy the opposing base (in a perpetual stalemate). The objective of the game is to power up your hero units (by defeating enemy heroes and computer-controlled units) until you have an overwhelming advantage, by which point you can mount an attack on the enemy base.
> 1. terrible at warding and dewarding
Dota has a fog-of-war system, inherited from its real-time-strategy roots. There are two main game mechanics that interact with the fog of wr: wards and smokes. Wards are stationary units that can be placed at a spot on the map to provide vision around them. Smokes are a consumable resource that can temporarily make your team invisible, so you can sneak through your opponent's wards undetected.
In regular Dota play, map vision is highly valued, to the point that there is a hardcoded limit on how many wards and smokes each team is allowed to use.
For all intents and purposes, OpenAI seemed to have no idea what it was doing with these mechanics. It placed wards at low-value places (instead of high value map intersections), and often wasted them by placing multiple wards on the same spot.
> are terrible at using spell spam to farm.
Farm in Dota means collecting resources to power up your hero by defeating dumb computer-controlled units (as opposed to by defeating the enemy heroes). The slang is because it is a relatively peaceful and patient way of acummulating resources. Farming is all about establishing control of a region of the map so that your team can defeat the computer controlled units there but your opponents can't.
OpenAI showed that it was very good at using their heroes' abilities to fight enemy heroes head on, but it wasn't as good at playing the "economic game" and using their spells to accumulate resources when there was no fighting going on.
> don't understand bouncing spells like the lich nuke
A handful of spells in Dota "jump" to nearby enemies after the first one, like a hot potato. Usually you want t ouse them when multiple enemies are next to each other but OpenAI was more willing to use these spells een when they didn't give an extra bounce.
I think that this might be a side effect of the AI's self-play. OpenAI has superhuman reaction times and is very good at positioning and moving around to avoid getting hit by those additional "jumps", so it wouldn't value them very highly.
> Bad at non-nuky/long running ultimates
Some hero abilities in Dota can be used very often (once every few seconds) while others have a longer cooldown time (once every 2 or 3 minutes).
In regular Dota play, you only want to use these major spells when contesting an important objective against your enemy, because if you "waste" them, the enemy team can take advantage of the time when your heroes aren't at their full strength.
OpenAI seemed to do a bad job at this kind of long term thinking. It would use some of its powerful abilities against computer-controlled units and then not have them available for an important fight vs the humans.
> Bad at judging Roshan respawn.
Roshan is a powerful computer-controlled monster that appears at the middle of the map. It takes a team effort to defeat, but the team that does so receives a very high reward.
After Roshan is defeated he shows up again after 8 to 11 minutes. Good players know that they can ignore Roshan for these first 8 minutes but that after that they must pay close attention to the area around its cave to prevent the enemy team from sneaking there undetected and defeating Roshan uncontested. OpenAI didn't seem to have learned this timing behavior. They would constantly check if Roshan was present in his cave, even in times when it was mathematically impossible.
> Are bad at juking.
Juking is trying to "break your opponents ankles" when they are chasing you around the map, by exploiting the fog of war. Enemies can't see higher ground or behind trees, so you can use those opportunities to quickly change the direction you are running in an attempt to evade who is chasing you.
OpenAI seemed to do a bad job of timing these direction changes. Ideally you turn to move in a different direction as soon as you enter the fog of war, no sooner and no later.
> not good at prioritizing cores over supports
In the later portions of a typical Dota game, 3 of the five heroes in each team will be very strong at fighting (the cores) and 2 will be weaker (the supports). Usual strategy is that it is more important to prioritize defeating the strongest heroes in the enemy team. OpenAI was more willing to go for the weaker enemies first, but I am not sure that is a bad thing actually.
> terrible at dealing with split pushes.
The most direct way to attack the enemy base in Dota is to defeat the enemy team in a head on fight and use the window of time when they are incapacitated to attack the undefended base.
Split pushing is a strategy where you try to attack the base when you think the enemies are grouped up far away from it and can't defend it immediately. The humans successfully used this strategy to delay the game, by forcing the bots to abort their frontal assaults and retreat to defend their base.
> bad at properly utilizing buybacks.
In Dota, heroes are incapacitated for a brief time after they are defeated. In the later parts of the game it is around 1 or 2 minutes in the sidelines.
There is an option to spend some resources (sacrificing future strength) to immediately return your hero to action.
This is a very high-risk high-reward play that needs to be timed appropriately to be worth the investment. The bots made some questionable plays around this game feature.
> 3. don't understand bouncing spells like the lich nuke. In fact many times lich used that spell as a poking spell.
I'm not convinced that their use of Chain Frost is necessarily bad. They are likely still used to their five man death ball strategy, where a single kill is often enough to secure a tower. In that case, using Chain Frost on a single hero may very well have better expected value with the guaranteed kill than waiting for an opportunity and potentially getting no kills, and even worse, pushing the game late where they cannot play effectively.
> 5. Bad at judging Roshan respawn.
This is technically true, but misleading. Humans determine this more accurately simply because we have been told the actual time range, but if you couldn't look it up, you would be bad at it too. You could try it in game, but imagine you weren't allowed to start a demo match, you were only allowed to do it in a live game. Furthermore, you have no access to patch notes, so you need to keep checking the Roshan pit in case they changed the respawn time. In fact, you don't even know that it respawns and then stays there. Maybe it only shows up for 30 seconds on every even game time minute, and disappears if it isn't attacked. Given the huge advantage that taking Roshan gets, maybe it is actually worth it to stick around there if you have no idea what the respawn rules are.
> 8. not good at prioritizing specific heroes in team fights (cores over supports, if both look equally chasable)
I didn't see this in the game.
> 9. terrible at dealing with split pushes. They prioritize defending their towers over everything. Also bad at split pushing, in general.
I didn't really see this in the game either. Axe was pushing, but what could they have really done about it? If they tried to wrap around and gank him, that would just split them up and leave them open to counter attack by the much stronger human team, particularly the Sniper.
In regards to the second point, in one of the caster games, the AI sacrificed Sven in order to secure the bottom T2 tower. Sounds like split pushing to me.
> 11. when they are behind, they simply don't have any coherent way of catching up other than taking huge team fights.
What would you suggest they should have done in this game then? It seemed to me like they didn't have very many options left at the end.
All in all I am very impressed by the AI. So many complex strategies that it is employing(grouping for towers, lane swaps, etc...). But at the same time, it really does look at the moment like this is only close because the AI has vast advantages from mechanics and teamfighting.
So I would say the superhuman-ness isn't in the number of actions taken, or in the response delay, but in the massive attention bandwidth. I believe they've attempted to even the playing field in the first two, which are easily quantifiable, but I don't know about the latter.
Similarly here, the AI can definitely do a lot more things at once, but each individual thing they do isn't very smart. For example, they waste money on useless wards or waste time sitting in front of Roshan. We can of course keep pushing the goal post, but I think if the AI can win with the given constraints, it's still a huge accomplishment.
Even more importantly though, it would be interesting to see if the AI is able to come up with new strategies and techniques that weren't known before.
Axe's Beserker's Call has a 500ms cast time. Euls is instant. Bots have a 200ms reaction time. Humans have 200-300ms.
The problem is the human doesn't just have to react to Axe blinking on top of them and decide to target him with Euls. Humans also have move their mouse cursor onto the Axe, which for a human is hard to do in 200-300ms (the time they have after reacting to the Axe blink).
A comparable situation that happens a lot is using BKB or Manta to react to a similar initiation. Pros can hit this counterplay much easier because they only have to press a keyboard hotkey, rather than move their mouse to a target first.
Lets look at casting a spell in a Dota. First I need to perceive my target. Then I need to move my mouse to the target, which is error prone. Then I need to press a button and click. Even for a human with extremely fast reaction time, this targeting phase will put you above 200ms easily, even if your perceptual reaction time was only 200ms.
The OpenAI bots don't have to target. They process their input, and take an action in just 200ms.
There may be situations where a human can make predictions, pretarget something and get a true 200ms reaction time, but in the general case 200ms is super human by a significant margin.
1) The Humans, Pain Gaming, is a professional team with players that regularly play and practice together and attend major tournaments. While they are the weakest team at this event and are arguably there only because of a regional qualifier system (they are from South America and the strongest team in an up and coming region), they are capable of taking games off some of the strongest teams due to their unpredictable and dynamic play. They are substantially better than the team of ex-pros and commentators that last played against the AI.
2) They removed an important limitation in the game, which was the 5 invincible couriers, and replaced it with a single killable courier that the five agents have to share (just like in a normal game of dota). The AI was able to use the single courier effectively, but did occasionally let it die a bit too often. What is important about this change is that it invalidated a strategy of the AI which was to continuously ferry consumable healing items to enable relentless aggression after gaining a slight edge in the early game. The AI adapted to this change by playing more cautiously in light of this standard resource/logistics constraint. It adds strength to the argument that as the OpenAI team introduces more complexity and resource constraints back into the game that the AI's weaknesses start to become more apparent and exploitable by better players.
3) The heroes composition was drafted in advance to be as even a match as possible, and a coin flip was made to decide which team got which draft. This is important as the version of the game is a subset of the game, and the humans evidently didn't understand the meta game in this weird subset during the last event. From the AI's perspective this was as even a draft as possible given the very small hero pool. In the last event the AI predicted 70-95% win confidence before the game even started due humans not understanding the drafting meta with a pool of 18/115 heroes and no bans.
Still, really impressive performance by OpenAI as at least for the early game and some of the mid game it was a close game with lots of good plays by both sides. The fact that OpenAI can be comparable to a pro team in what is nearly a full game of dota is really impressive.
I think it's totally disingenuous to call them the weakest team at the event. Two other teams performed worse in the group stage and one tied Pain's score, but still made it into the main event through sheer luck. Pain has won games against every single one of the strongest teams there.
If you follow pro Dota, you know a lot of these games hinge on how a team happens to be performing on a certain day. Just this past May, Pain played in one of the top Dota tournaments of the year with 9 other teams who also happen to be at The International with them now -- and Pain came in 3rd place, ahead of Fnatic, OG, and Mineski.
In that paragraph where you selectively quoted you removed the clause where I said: "...they are capable of taking games off some of the strongest teams due to their unpredictable and dynamic play", which is is no different to the point you are trying to make.
Fact is, they came last, they were lucky to attend given it was a surprise that their region was given a slot for the first time ever, but proved themselves to be a capable team from a region that is starting to get international exposure, and you are deliberately misrepresenting me.
This team isn't the strongest (they placed 17-18th during this TI) but OpenAI will play again tomorrow and the day after, presumably against progressively better teams.
Oh, is that all :P. Assuming a 2x buffer for players who are good but not competitive, there are maybe 200 humans in the world who are better at DotA. If mastery is 1 in 10,000, these people are masters.
Seeing OpenAI do so well against this team impressed the hell out of me.
Actually, "weaker" (top 20) teams regularly do take games off better teams so I don't think there's much evidence for an exponential skill increase between teams.
I'm unfamiliar with DOTA rules, but does anyone know if there are any limitations on the openAI team? e.g. Things like keystrokes per minute, scroll speed, etc
If this game was balanced around AI rather than humans, this game would look very different.
If OpenAI wishes to have human-like mechanical limitations to make things more about strategy, then they should definitely start adding some sort of action performing delays to actions based on roughly how long a skilled player would take to do them.
- Random Draft using a pool of 18 heroes (Crystal Maiden, Death Prophet, Earthshaker, Gyrocopter, Lich, Lion, Necrophos, Queen of Pain, Razor, Riki, Shadow Fiend, Slark, Sniper, Sven, Tidehunter, Viper, or Witch Doctor)
- No summons/illusions
- 5 invulnerable couriers, no exploiting them by scouting or tanking
- No Scan
Not sure if this match has the same limitations, but all heroes in the current game but one (Axe) are in list above, so maybe they added a few new heroes to the allowed pool.
They had a fixed draft from the above pool with 1 new hero:
Crystal Maiden, Death Prophet, Tidehunter, Gyrocopter and Lich
Lion, Necrophos, Sniper, Witch Doctor and Axe (the new one).
Once OpenAI Five defeat 3-4 pro teams convincingly, it could be presumed from the observation above that they will defeat any other top teams within a year at most, if sufficient resources are used for improving the AI. An exception is when a fundamental hidden weakness is found in the AI.
Another confounding factor is major rule changes where the game essentially becomes a different one.
Not sure how you intended this, but the hero pool constraint is actually an enormous advantage for the AI. The current hero pool isn't, by any means, random. I don't know OpenAI selected it, but it's highly conducive to OpenAI Five's strengths--deathballing, mechanics, teamfight coordination, etc. It lacks essentially all of the heroes that humans would normally pick to counter that strategy.
Playing on an unrestricted hero set would test OpenAI Five in entirely different ways than playing on the current hero pool would. I would not be comfortable betting on your statement at all.
Isn't it the other way around - openai adjusted to the hero pool to come up with its' strategy, because it was trained on this hero pool.
If hero pool had only late-game melee carries - I assume openai would come up with a strategy that works with that.
My guess is that if OpenAI 5 trained under a different hero pool, it would be weaker than it is now. It's very hard to predict how much weaker though.
Some of the restrictions they've discussed - like initially they couldn't handle with illusions, summons or invisibility at all. They obviously dropped the invis restriction.
My feeling is that the AI just learned that of the given pool, 'deathball' was the best (and specific heroes like Gyrocopter/Sniper were the most effective carries).
Not to take anything away from Pain--just making it to TI is
enough to prove that they're excellent Dota players.
Crappy garena, banlists, vs 5 ai in wc3 when no internet... :')
Yes and no. By raw numbers it certainly is in a state of decline. But put in context, it may have been inevitable. It has everything going against it.
DotA is a team game.
It's incredibly complex. Not easy to pick up. Mastery requires 1000's of hours. And it's miserable to play at the start.
The community is toxic. So random teams in a public match when you are new to the game compounds. Even if you aren't new, one way or another random teams can quite often be a frustrating experience that you just don't feel you have control over.
Compunding even further is the fact that once you start a game you are locked in for 35-55+ minutes. That can be 35 painful minutes of feeling crap.
Compare that to rising battle Royale games, and you get solo games you are allowed to be bad at and slowly get better in. And the time you spend in it is directly related to how much fun you have. And the games have a definite time cap. And the mechanics are simple. This holds true for a lot of other up and coming online casual multiplayer games.
Point is, Dota is destined to be niche as a game that is played.
What i would love to see is how the game can change externally to become more accessible to viewers. From client changes to community changes to changes in presenters, valve needs to step up to help people participate as spectators. The potential for the game to generate significant money lies in their pro circuit and it looks like valve is really stepping up their involvement here. Hopefully this continues.
The (somewhat poor) parallel is something like rugby or squash. Fairly arcane rules. A lot of people don't remember when they last played the game. But they can still be heavily invested in watching.
DoTA is incredibly complicated, and has more compounding interest towards tactical strategy + gameplay + teamwork + skill execution, more so than battle royale.
In battle royale, if you played awful you just die. Then you start a new game. With DoTA that death impacts your game in the long run, putting your team at a disadvantage, since you just fed their carry. But comebacks do happen though
Going to DoTA TI:2 internationals, where all the major esports teams compete is different than anything else you've ever experienced.
Its like going to the superbowl. Except, everyone knows how to play football, usually on an average / above-average level. But, instead of a few hours, its 8+ hours, for 7+ days. It gets EXTREMELY intense, just because you because you can relate to how difficult manuveurs are, and it isn't dictated by things like how much weight you can squat in football (For faster sprinting / agility, etc). There's many little minor mental and physical gymnastics that DoTA2 pro players do 100xs better than your average player.
Comparing this to Fortnite competitive mode, its not the same. Its more closely tied to watching something with less strategical depth, such as tennis. Tennis is still exciting for its own reasons, but its mostly skill based execution, and mostly a solo game. Even if you played 2v2.
I watch both fortnite and dota2 competitive every so often
(it seems to work only for their own event at this time tho.)
It still have limitations and bugs, yesterday it just wouldn't load for me, but it works now, and you are unable to watch yesterdays content.
People complain a lot that Europe is stacked (meaning stronger teams) compared to regions like NA, and they get the same amount of slots a TI. South America is probably the weakest region.
I think a lot of people following the competitive scene would agree with what he was saying - that Pain is not top 20 in the world.
> People complain a lot that Europe is stacked (meaning stronger teams) compared to regions like NA
Really? Go ahead and name an EU team that is not playing in TI that should be here. EU is top heavy and they get to TI easily, other than that not much. SA is weaker region for sure, that's why they have 1 team from their region and they deserve to be there.
One thing you can see is which team is constantly defending and which is constantly attacking. That's a pretty good indicator too.
No guarantees though, games have been known to flop and be unpredictable, mostly due to respawn timers / buybacks lategame. Late game is super critical on who gets first kill generally
You can see net worth gold difference by looking at the text that appears in the top center which normally say something like ">1k" for one of the two teams. Its something they recently just added to the spectator UI.
The sliders you mentioned on left usually show individual player net worth, so you can see where resources are being allocated on the team. The "observer" (a camera man I guess) picks which stats to overlay in the top left over the course of the game depending upon which single indicator is most relevant.
In the early game those sliders normally show "last hits/denies" per player, which is about collecting early game resources. In the mid/late game its usually net worth per player. In the late game it starts looking at a thing called "buyback status", which is an ability all players have to spend a lot of their resources to rejoin the game early after getting killed. Using "buyback" is very expensive, scales with networth, and has a 5 minute cooldown.
Not always a great indicator but you can tell who's behind.
- poor warding. Some wards were simply wasted. (Wards are small, invisible, immovable units that grant vision)
- using powerful long cool down spells to earn gold instead of keeping it in reserve for fights
- not recognising that one of the lanes needed to be pushed out. Eventually this bit them in the ass.
- using buybacks where none were required
I always disabled joining wards, but when I forgot - I warded like openai, because I had 3 obs wards on top of a sentry and needed to put a sentry somewhere :)
for humans, wards give you extra time to react to enemy movements and arrange ganks, check runes, etc. but the robots don't really need the reaction time bonus, and the information bonus may not be very valuable if they arent proactive about pushing and ganking.
I think I saw somewhere that they are training to consider a time frame of a minute or so, so it makes sense. But it's also slightly disappointing since these games have long term strategy when teams are evenly matched.
Mechanics and positioning looks really strong still. Decisions less so.
Very good play from OpenAI though, even though it ultimately lost. It looked very scary how fast it could switch between dominating 5-man teamfights to splitting up and ganking or pushing down towers.
I doubt a player is about to react to a blink initiation and click Euls/Hex in the same amount of time. It'd be a lot more fair for them to calibrate against the reaction time of pro-players across the same scenarios. (I doubt pros can hit 200ms consistently)
I think this is bit of a red herring: while that's true, OpenAI isn't competing against 99.99% of humans -- they're competing against the top 0.05% of Dota players that very likely have a much, much lower average reaction rate.
To throw numbers at it, https://www.humanbenchmark.com/tests/reactiontime/ has the top 10 people at ~110ms, while I (at a measly 1K MMR in Dota) can pretty easily average ~220ms (and they report human average around. I imagine pros in the scene have honed these reflexes to be far superior than the average human.
 Also worth noting that they discard all reactions <100ms, so we could have some <100ms prodigies that actually have faster reaction time than the 100ms reported on the scoreboard for them. (These numbers are spread over 5+ trials, so "getting lucky" is a lot less likely.)
I think OpenAI might have a bug with how they're adding reaction time.
I find it amusing & ironic that they're pursuing games of efficiently & strategically killing enemies as examples of their successful progress. ;-)
Except that the amusement and irony would cease to exist once you have some idea of what's happening behind the scenes.
The AI doesn't know it's "killing enemies". For it, it's just something that results in the increase of a numerical reward signal.
Stepping back a bit and simply looking at the context, though, it is an amusing contrast.
Go OpenAI! I For One welcome our new robot overlords.
Interesting that OpenAI seems to prefer deathballing, but it makes sense: its main advantage over humans is probably tactical and in teamfights, and 5-man maximizes your options. The human strategy should probably be to split push, but one of the commentators (who is also a pro who played against OpenAI earlier) says that is very difficult because OpenAI can apply pressure everywhere.
The actual point is that AI's advantage were using tactics and strategies that human opponents would find unintuitive, or even counter-intuitive.
How AI comes up with those tactics is not at all relevant to this thread.
"Feed" is a term in Dota when players (aka Heroes) die without any benefit to your team--such as destroying an enemy spawn (racks/Barracks), killing another team Hero (hopefully more one). It's "feeding" as the other team members nearby will get gold and experience for each kill. As there is a respawn timer, the character who is dead will not get Exp nor Gold during that count-down resulting in a character that is disadvantaged as it will be under leveled compared to the rest of the heroes.
In the early and mid games of Dota, not gaining experience and gold is a major setback. Dying has a huge penalty.
The term "feed" is used with players who are learning the game, or those who are low skilled, and are haven't yet mastered some of the main aspects of playing. They're dying with no benefit, boosting the other team.
"Mid" simply means 'middle lane.' DOTA has 3 lanes, top, middle, and bottom, and short hand refers to them as top, mid, bot, respectively.
If your team is losing, boosting the other team to get the game over with is poor sportsmanship. A single team battle could easily shift the game into the losing teams favor.
In sports like Football, you may see teams pull their starters to 1. prevent injury and 2. give other teammates experience, but you'd never see someone purposefully help the opposing team win.