Extreme Chess Analysis (ECA)

What is Extreme Chess Analysis (ECA)?

ECA is a feature to build minimax trees for given starting positions. Nodes of those trees are typically decorated by computing info such as scores.

ECA can help users to analyze deeply chess positions and collect much more information for variants.


What do ECA’s trees use for?

ECA’s trees could be used for:

1) Deeply studying

It is the main purpose, especially about openings. Players could dig information on the trees to find traps, alternative moves, and variants, explain why these moves but not that moves, and how good, how bad a line compared with other lines. They could get overall views when starting from a position.

2) Create opening books based on computing

There is a kind of opening book which based on computing (typical opening books are based on game data). The tree which starts from the chess original position could be exported into that kind of book.

3) Reuse computing (developing)

The tree could work as a bank or a dictionary of computing. For a given position we can try to find a matched one from the tree. If found, we can extract information instantly without computing.


How different between ECA trees and engines’ search trees?

Almost all engines use AlphaBeta algorithms for searching. That algorithm trims almost all branches but keeps only a small number, around the best line (PV) only. The tree may be so deep but so narrow. In contrast, ECA trees are much wider and could have full branches.


How different between ECA and Analysis functions?

When analyzing in the traditional way (using Analysis functions), BSG controls engines to compute each position of a given game and the engine will give the score and PV of each position. Even though we could consider all analyses to become a form of a tree but basically that tree has only a main branch/backbone as that game itself and some extra branches by PVs. Users could have a good knowledge/view about that game only but not general information. For example, at some point, users may know the game made a bad move and what is a good move but they don’t know about alternatives as well as further development of them.


How to use

1. Turn on the ECA panel

Menu → Analysis → Extreme Chess Analysis

The panel is typically displayed on the bottom. If it is hidden by other panels, just find and click on its button. Users may resize it for a better view.

2. Create a new project

Click on the button “New project”, select folder and name then enter.

Rename the project: just double click on the name of the project and enter a new name

3. Turn on the project

Select tab “Project”. Double click on the column “active”, select “true” and then enter. ECA will load data of the project, verify then display “Ready”.

4. Computing

Just click on the “Start” button. ECA will auto-start computing. There are two phrases continuously:

  • Evaluate

ECA will evaluate all leave nodes using the given engines and concurrency.

  • Expand

a. Auto expanding

Auto evaluate nodes and expand them

b. Manual expanding

Auto evaluates nodes but does not expand them. Users should expand them manually.


5. Examine the tree

a. Flat tree in the tab “Nodes”

Mouse: click on buttons, double clicks

Keyboard: use arrow buttons, enter, home, pages, W, A, S, and D for faster navigation

b. Tree structure

Similar to flat tree.

c. Tree image

Good for overview but not many details