Opens up a new window with only a chessboard and tools on it, where you can drag the pieces freely with your mouse to any square you wish. In this way, you can setup any position for rational analysis, using engines (calculation modules), endgame tables, or “Monte Carlo” analysis.
You can open simultaneously up to 4 auxiliary boards. Every time you open a new board, it displays the same position as the main board.
If no calculation modules, opening books or databases are registered, their respective buttons in the toolbars will appear disabled:
When you register a calculation module, the tools in the first row will activate, registering an opening book will activate the tools in second row and finally, registering a database will activate those tools in the third row.
To put a piece on a precise square of the board, you click first on the piece and then click with the right mouse button on the square you wish to put it. To move a piece, simply drag it with the mouse.
To return to the current position, press the start button ( ), located in the upper-right corner of this window.
On the upper right corner of the blackboard yo will also see the button:
When you click on it, the image changes to:
And from that moment on, the board will remain always in the foreground of the screen, on top of other windows or applications.
Using the engines.
The analysis of games and positions is made from this window. Just select the engine from the dropdown list in the top of the window, and press the button (
) This will start the execution of the module, using the calculation options defined in the configuration of the engine:
And then the module will begin analyzing indefinitely, displaying details on the bottom of the window:
For the analysis to take place only until a certain depth, before starting the calculation, you need to enter the number of moves in the textbox to the right of the label "Prof.", at the top-right side of the window. It is also possible to limit the calculation time in seconds by entering a value in the textbox labeled "Segs".
If both optional values are specified at the same time, the time value takes precedence. To search for a checkmate, you check this option and the number of moves in the "Prof." textbox. For example, to find a mate in 5 moves, just type 5.
To stop the calculations at any time, simply press the button (
).
If at a given position, we want to analyze a single move, you enter it in the textbox just below the label "Jugada/s" in simplified algebraic notation (initial square-destination square, for example: c4d4). Not all modules accept this possibility.
The data related to calculations are the following:
At the bottom of the window the analysis data is displayed
In the first row, from left to right:
22 Search's depth
45 Extended Depth (up to where it can go in variations with captures and checks)
1810168 nodes per second that the engine is currently evaluating.
g2g1 Move under consideration
4 Number of the move being analized from the total for all the possible moves
11 Total of all possible moves
13388 Number of positions in tablebases
1224678 Number of positions in the shredderbasses
56,875 Calculation time in seconds
The second line shows the best variation found so far and its evaluation (-1,71).The assessment is always done from the side to move, therefore, a positive evaluation means an advantage for the side to move.
In the third and fourth lines are shown the second and third best alternatives. These lines appear only if the engine accepts this possibility and you have specified a value of 2 or 3, for the option multipv. Values above 3 are not useful, because it will slow down calculations and further lines won’t be shown
When the calculations are completed, or stopped, the most relevant information is shown and some buttons are enabled so that you can replay not only the main line, but also the second and third lines. The first button toggles between the lines calculated.
The "Copiar",
button stores in the clipboard the variations currently displayed.
The first element in the list of engines is: "No module" and the second: "Monte Carlo". The first allows to find in a game all positions that are present in the active database, using the button (
) from Analysis of a game. The "Monte Carlo option", examines a position in the same way as does the (
) button, but also allows analyzing all the positions from one or several games, with the buttons (
) and (
).
Analysis of a game.
The games are analyzed from the last move backwards. This increases very considerably the calculation power, because when analyzing a move, the engine has already calculated all the other moves that occurred after it, and that fact provides useful information for the logical evaluation of the analysis.
The analysis of a game includes not only assessing every move but also indicating, where appropriate, alternative continuations to what was actually played. Besides, the opening is identified and, if you wish, you can search the active database for games that at some point reached any of the positions that appeared during the current game. It is important to emphasize that the Viewer will search for identical positions, not by identical sequences leading to that position, so the move order is irrelevant.
In the textbox to the right of the drop-down list of databases, which by default takes 5, you type the maximum number of games to bring from the database to include them in the analysis. The matches with the games from the database are more interesting as the game is more advanced, as the analysis starts at the very end of the game and then comes backwards. So the limitation of the number of games will affect the items closest to the start of the game. If you write a 0 in that textbox the database will not be consulted during the analysis
To analyze a game, you first set the options that are discussed below and then press the button (
). The application will request a file in which to write the results in PGN format.
Analysis options.
The analysis to each move, will last the time specified the textbox "Segs",
or will be performed until it reaches the depth indicated in "Prof". If nothing is indicated for any of these two textboxes, the Viewer will analyze each move for 5 seconds.
To the left of the window you can see the options "v"and "p".
When they are marked, the result of the analysis will include the assessment of the position after each move made and the depth of calculation.
Through the textboxes 2 and 3, highlighted in the picture below, you can specify the first and last moves to be analyzed, if left blank will be from first to last.
In the textbox labeled as 1, you can enter a value (100 = 1 pawn) to establish the minimum assessment which is considered significant for the application to include a variation in the analysis. If the analysis finds a different move to the one actually played, and the difference in the evaluation of the position is greater than the indicated value, then the application shall include in the analysis result, the alternative move found as a better option, otherwise it will be ignored. A normal value is 50.
In analyzing a game, the same time is used for all moves or you arrive at the same calculation depth, unless you have marked the box"r":
If the box "r" is checked, each time the module finds a move that is better than the one actually done, and the improvement in the assessment of the position is greater than the indicated value, as stated above, then the Viewer will conduct a more thorough calculation, spending three times the normal time on it or to a depth of two more moves.
When analyzing a game, the following window opens up automatically:
At the top you can see the evaluation that the engine makes about the position after each move. Positive values, in blue, mean advantage to white. When black is better, the evaluation is represented by negative values in red. The white moves are shown in light colors, and black moves with a darker shade.
The bottom graph represents the errors, calculated as the difference between the value that would have been obtained from the best move and the value of the move that was actually played. Placing the mouse over any element of the graph will show the exact value of the element.
The first of the two other small buttons, in the top-left of this window, allows to save the graphic into a file in the typical formats (BMP, GIF, JPG). There is also the possibility to save it as a text file (TXT), in which case, a three column list will be saved for the move number, the evaluation and the error value.
The other button changes the window size, which can also be modified by dragging the mouse to the edges of it.
In the lower left corner, there is a square which can be red or green. Allows you to set whether this window should always remain visible (green) or be hidden if we go to another window (red). To change the status of the window click on this box.
If you close this window and want to open it up again, press the button (
), located on the toolbar.
The analyzed games are stored in a file in PGN format. Extra information is added so that the graph of the previous image can be built. Later on, when you replay the game in the main window, in the right side you will see the button (
), which allows to view the graphic, if clicked.
In the analysis of games, the best continuation is included, provided that the game did not end up in mate or stalemate.
The analysis of a game ends when it reaches a position which is contained in the opening book currently selected. That information is included in the record for the game, as a comment, inside the moves sequence.
Analyzing several games.
If you want to analyze the full list of games that appear in the main window of the Viewer, use the button (
). The first game to be analyzed from the list, is that on which the cursor is located.
As for any game, you must first specify a file where it will be saved in PGN format
Analysis on the fly.
When connected to an online gaming room, it is possible to open a new blackboard with the button (
) from the toolbar of that window.
In the upper-left corner of the blackboard, you have the buttons:
These two buttons launch the selected module to begin analyzing the game being played at that time in the board room where we are connected. For more details see here,
the chapter on access to the rooms online.
Using books openings.
The opening books allow knowing if the position on the board corresponds to a game that has been played before. Besides, they helps us searching for the specific opening of any game. If the position exists in the book, a new window opens up:
The contents of that window are described in the chapter "Opening books", see here.
Using the games database.
Besides searching for games during a game analysis, you can search in the current database for the position on the board. If there is at least a match, a new window opens up:
All about the possibilities and options available in that window is described in the chapter
"Games databases", under the section search position.
Use of endgame tables.
In the chapter "Endgame tables" it is described how to use the endgame tables to find out the result of the current position.
The "Monte Carlo" method .
This method consists of generating, from the position on the board, many games selecting the moves at random, to see if they end up with the victory of either side. For each turn, a list of possible moves is generated, according to the rules of chess. Then a draft takes place, where all those moves have the same probability and only one is chosen.
The number of games to simulate, is set in the textbox to the left of the button (
). The number of games will be the number you enter multiplied by one thousand.
If one side gets more wins, it indicates that, generally speaking, the starting position is favorable to that side. This is truer the more "positional" is the character of the position. On the contrary, it will be less true when there are tactical factors in the position.
The data shown by the Monte Carlo analysis are the following:
In the first line you can see the number of simulated games. In the above image: 93600.
In the second line and in this order:
Evaluation adjusted to the number of pawns (-0,02).
Positive means better for White and negative better for Black. The evaluation is independent to which side is to move.
Evaluation as a percentage of points obtained in the simulated games. A value above 50% means white's advantage. In the above image: [49.77%]
Number of victories for the white pieces. In the above image: 16479 +
Number of victories for the black pieces. In the above image: 16917 -
Number of draws. In the above image: 59777 =
Percentage of games that have ended with the victory of either side or a forced draw. The viewer assumes a maximum of 900 moves per game, which ensures that, in general, over 99% of games finish earlier. In the above image: [ 99,5% ]
Note: For purposes of the simulations, the viewer has the following approaches:
Considers "a stalemated king" as checkmate.
Always promotes a pawn to a Queen.
Disables the 50 moves rule for draws.
The only forced draws are king against king and king against a single minor piece.
Result of analyzing a game.
The following image shows the result of the analysis produced by the Viewer.
In the above image you can see the annotations in the opening, based on games found in the database, reaching those exact positions.
In this second image you can see a better continuation than what was played after 34 ... Kd6. Finally, the best continuation of the game at the time Black resigned is shown, according to the module used.
The blackboard. 
), located in the upper-right corner of this window.
) This will start the execution of the module, using the calculation options defined in the configuration of the engine: 
).
) from 
) button, but also allows analyzing all the positions from one or several games, with the buttons ( 
).
), located on the toolbar. 
.
