Help Needed - How to Play Against Influence Style Players

So I recently got into a personal feud with Cosumi (level 5) and got my ass beat really really bad. For those that don’t know, Cosumi is an AI that EXTREMELY favours influence. I am a strong 1k/weak 1d depending on how serious I play, and I’ve read elsewhere that Cosumi level 5 is equivalent to 1k on OGS. I don’t doubt this conclusion but I noticed that Cosumi has a 80-90% win rate over me. I think this has to do with Cosumi’s style - I am typically stronger playing relatively balanced games and am terrible when my opponent solely plays for influence.

In one of the games I played with Cosumi, I took most corners and sides and Cosumi had a huge moyo closing around the center, which if uninvaded, easily has more points than all the points I have. I was very certain that I’d lost the game, but when I ran it with AI, I had a 50%+ win rate right before I resigned.

For those of you who find it easier to play against influence or play for influence yourselves, please provide some tips on how I can improve in games like this.

I haven’t figured out how to download Cosumi games, but here’s a re-creation of one of my games. At this point I felt pretty hopeless, but AI says white still has 55~% win rate.

Coordinates and game record are missing, so it’s not easy to discuss the game. Also, 55% winrate doesn’t tell us much. Strong AI are very good at moyo reduction, so it may just be that the analysis AI sees something that no human of your level would be able to pull off.

From what I can tell from that picture, white has some stones that seem slightly overconcentrated/inefficient to me. So perhaps white played a bit passively, but I’m guessing here.

I (3d) might also feel behind with white in this position, but I would definitely not have resigned without even trying to break into black’s moyo.


Here is my advice:

Never, ever, resign a game without counting the territory first. No matter how “hopeless” you feel.

That is very true in general. But in the game shown, black doesn’t have a moyo. Black has a territory. At this point I would call it “endgame” rather than “moyo reduction”.

And I would add that reducing Black’s northeast corner looks more important to me than reducing the centre territory.

I guess it depends on a player’s judgment on what a “territory” is. To me, the center looks pretty much like territory as you put it, and if that’s the case, black has more or less the same points as white (~45 points) just in the center, and the top right/left side looks sufficient for komi. Thus I resigned.
Clearly this is not how AI sees it, white must be able to largely reduce black’s influence/territory to have a balanced win rate.
My question is, do you find these ways of reduction/invasion apparent (they aren’t for me)? Is there something I can do to better spot these moves?

Sorry about that, I don’t remember how the game went exactly and this is a re-created game based on my memory. I included this one just as a demonstration, but I’ll try to upload actual games next time.

How about trying to counter your opponent’s influence before it’s too late?

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Peep that one point jump on right and attach looks like a hole in the moyo boundary. Black’s strongest reply to peep may be counter peep, but then you get some nice side profit whilst reinforcing your lower left corner, which isn’t totally secure yet.

Also hane top right corner, or maybe even some submarine on top side aiming at peep from inside.


Here are a few questions about the current board:

  • What is the status of the white group on the west side? (the four white stones who captured one black stone on the second-line)
  • What is the status of the Black group in the northeast corner?
  • How much territory are White and Black going to gain on the north side of the board? There is a huge area with no stones on that side.

Here is a summary of these three questions as a go board with big red question marks:

If the answer to any one of these three questions is “I don’t know”, then the game is certainly not “pretty hopeless” and it is way too early to resign.

I don’t understand. You’re counting that Black has about the same number of points as White, thus you resigned?

What is your rank? How close are your games typically?

I ask because endgame is an important part of the game. There are a lot of points to be gained in endgame. At 1kyu on OGS, I think it’s extremely common for a player to reduce or increase the gap by 25 points during endgame, just by playing a better endgame than their opponent. What this means is that if your game is close then you should absolutely not resign. You can still win just by playing a strong endgame.


Sadly many kyus are taught that it is rude to continue a game if you are behind. You should resign so as not to waste your opponent’s time. Of course kyus are also bad at reading and counting so many mistakenly resign close or even winning games :pensive:

I tried and went 4-1 against level 5 cosumi. And I’m bad at this so you can surely do it.

To defeat this cosumi you need to fight. It makes mistakes then (on purpose to keep appropriate difficulty level). If you try to calmly make better exchanges then it’s gonna be harder, these AIs are good at evaluating. In one game I lost I didn’t fight enough.

A sure way to win is using this opening as black:

And in general playing better moves help.

You read it wrong. I was saying black has about the same points as white ONLY counting the centre (assuming no effective reduction), and can easily make up for komi with the left and top right (black will get at least one of the two).
I get your point about endgames and I totally agree. The point of this post isn’t really about how to win against Cosumi, but how to counter this playstyle.

Thanks! I also found fighting a pretty good strategy and my win rate was a lot better that way. However one of the reasons I played Cosumi & made this post was to learn how to maintain my preferred style (playing a balanced game) against an extreme player like Cosumi, and not just to win.

What did I read wrong? You said exactly the same thing again. If this is your evaluation then why did you resign?

By worrying less about Black’s centre territory, and more about the three big question marks on this board. The game is far from over. However, Black’s territory in the centre is a territory.

There is no “judgment” about the centre territory at this point. It is a territory, period. At this point, the “reductions” of the centre which you are looking for are going to be small endgame moves.

Perhaps earlier in the game there could have been good ways to reduce the centre, but that’s gone now. At this point in the game, the territory in the centre is done. So stop worrying about it, the reduction moves are going to be pretty small; and worry about the big moves instead. The big moves are around the three big question marks: life of the white group on the west side, situation of the black northeast corner, and potential territory for both players on the North side.

So you resigned because of something that Black could maybe do in the future? Don’t resign because of something that hasn’t happened. “My group might die in the future” is never a reason to resign. Your group isn’t dead, but you resigned because black could maybe kill it in the future.

Sort of, maybe. But the important question is: how much of it is secure territory?

I consider it quite fuzzy where the boundary of black’s territory is exactly. KataGo also isn’t quite sure, it seems:

Edit: my KataGo thinks the game is close.


No, but it’s very likely that Black will get either the top or the left side, it’s called Miai.
Based on your profile I think you’re a stronger player than I am, so I’m sure you can see what I can see. It feels like you’re a bit emotional in this discussion and it leads nowhere.

Black’s stones in the center are clearly not territory if played correctly. Just as Uberdude said, there are still holes in it, it’s just I didn’t see it/saw it but wasn’t sure how to execute it.

But thanks anyway for that.

Here’s a game I just played (can you emded sgf?). Was leading after first fight, but extended it a lot when it played a load of gote centre moves so I played bigger moves on the sides (Note 4th line left middle to stop being pressed low) and then reduced before centre could close and it let me walk right in. Won by 50 points despite falling asleep ay the end to let a dead 3-3 live.

Gote moves to build a centre are rarely efficient enough to win the game, so you can calmly take more profit and then reduce. It’s if you have a weak group that allows them to build centre in sente that centre can become winningly big so that’s what you’ve got to watch out for.

(;GM[1]FF[4]PB[COSUMI(Level 5)]PW[You]SZ[19]KM[6.5]RE[W+50.5]

I think that’s what happened in most of my lost games :joy:
Maybe I need to work on maintaining strong shapes?

For example, I would like to move these marked stones to a different location:


Yeah, improved understanding of strength and weakness of groups is key to improving around this level.

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I’m sorry if anything I said sounded “emotional”. I have no idea why it sounds that way and it wasn’t my intention. I tried to answer your questions and give my evaluation of the position that you have shown us.

I thought I was giving a clear explanation that the game was far from over and that the three areas which I pointed out were much more important in that game than reducing the centre.

I asked you what your score estimation was when you resigned and you answered that Black and White had approximately the same score. I’m telling you that in these circumstances you shouldn’t feel pretty hopeless.

I asked you if you knew for sure what would happen in the three big areas, and I said that unless your were certain that Black would get everything in all three areas, which means killing your west group and taking the territory in the north side and in the northeast corner, then you shouldn’t resign. Your answer was something vague along the lines of “surely black might gain something somewhere”. I’m telling you that this isn’t a reason to resign.

What Miai are you talking about? If you’re talking about Miai then I assume you have read two sequences, one where black wins by killing your group, and one where black wins by taking all the North Side territory? I don’t know what those sequences are. Just because I have a higher rank doesn’t mean that I can guess which sequences you are talking about. In fact I highly doubt that you have a specific sequence in mind. It really sounds like you resigned because you felt like black could maybe gain something vague in the future.

I think that this discussion is not leading anywhere because you don’t want actual advice, you just want us to agree with you that Black’s territory in the centre is big. Okay. Black’s territory in the centre is big. Have a good day.