DieterVerhofstadt/Patterns in 2021 ABC of mistakes

Sub-page of DieterVerhofstadt

In 2021 I've played 100 games and analyzed them with KataGo. In each game I have identified the 3 biggest mistakes, defined by the biggest shift or swing in points, not percentages, as indicated by KataGo. This results in 300 "mistakes". See /2021ABCofMistakes Two assumptions inspired me to do this project:

  1. I will find patterns in these mistakes, which show a possible improvement to my game
  2. Patterns in mistakes AI finds in my game, are relevant to other amateurs or lower dans.

Indeed, patterns emerged, while you can argue the human mind is built to find patterns even where there are none.


One is a "non-pattern", where I found the sequences supporting KataGo's suggested move too hard to interpret. Usually it's about the relative strengths of multiple groups, which can move from healthy to being in danger, depending on cuts and connections around the board. With my conceptual understanding, the improvement just boils down to "reading very deeply" - which is the basic criticism on reviewing with AI. A related known concept is global thickness or atsusa.

Another is a "trivial pattern", where I missed a sequence on my level or below, mostly about the life and death status of a single group or the liberties in a 1-1 capturing race.

But there are more ...

Slow connections

One emerging pattern is the slow connection. I have a tendency to make hanging connections, table shapes, bamboo joints ... without too much thinking, even because of the visual shape, while it protects against a cut which is not necessarily harmful or urgent. They look like honte and maybe can be considered as such, but AI finds them slow to the point of losing 5-10 points.

Heavy cuts

Closely related are cuts or reinforcements of cutting stones, where the opponent's groups are already relatively strong and the cutting stones end up as a heavy (central) group.

Wrong cutting or connecting techniques

In some cases the cut (or connection) is valuable but the choice for the cutting technique is wrong. Usually I'm employing a move that looks like good shape but in this case is not working as well as another move, which is more crude at the surface.

Applying pressure

Another, more difficult pattern, yet within my reach, is that of "applying pressure", which reminds me of John Fairbairn's promoting the term ijime, which he translates as "bullying". There are two subsets of this pattern.

  • The first one is about when to play elsewhere. We know that AI values playing elsewhere earlier and higher than we traditionally did. However, there are still cases where AI wants to continue locally and this is when a group can be "bullied" into some kind of submission, like small life. You could probably think of this as the sharp version of attack while still not going for a kill.
  • The second one applies to situations where one is under such an attack. Rather than being "bullied into small life", there's often an option to counterattack from the other side, "bullying the opponent into small capture". Or even better, bullying the attacker from the outside, before accepting small life. You can think of this as a flavor of forcing moves.


The last pattern is related to (my failure in) dealing with moyos. I tend to invade too deeply, or too soon. I'm pretty good at following AI's opening gospel, but when my opponent builds a moyo from consecutive exchanges of influence for territory, I'm not as good in reducing or invading those, or timing an invasion. KataGo is pretty comfortable at "high invasions": creating a living group in the middle of a huge moyo or with the option of escaping. It will often prefer those to the deeper invasions, which can be more easily killed or "bullied into submission". It will create such central groups fairly late in the game, later at least than my (premature) side invasion. When the moyo is smaller, KataGo will often choose not to invade and rather build elsewhere to match the potential territory formed by the moyo.

DieterVerhofstadt/Patterns in 2021 ABC of mistakes last edited by Dieter on November 16, 2021 - 17:15
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