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Analysis Windows

Scid vs. PC has powerful chess analysis features. Multiple engines can run simultaneously; they can be matched against each other in a Computer Tournament, and log files can be browsed from within the app - making for easier Debugging.

Getting Started

A few engines come preinstalled, while others can be added via the Engine Configuration window.

Starting them can be done in various ways By pressing F2 , F3 or F4 from the Configuration Widget, or via the Tools--> Start Engine menu. Additionally, Engine 1 can be start/stopped by double-clicking the statusbar. Right-clicking the Statusbar will dock/undock the engine, which, when running docked, will run at low CPU priority.

Space Bar is bound to engine start/stop. Pressing Enter will add the engine's current best move, and Control+Enter, the whole line.

At the top of the window are some useful Buttons. Engine Analysis occupy most of the space, and at the bottom is some Extra Information (which may be hidden).

The analysis output has three modes: No wrap, Word wrap, and Hidden. These are toggled between by right-clicking the analysis window.


At the top you'll find many cryptic buttons...


Each line of the main text widget contains an Engine Analysis Info. The first number is the current Search Depth. The next (prefixed with a +/-), is a Move Score. It is measured in pawn units from the perspective of white - a positive score means white is ahead, a negative score means black. Then follows the move predictions.

Many recent UCI engines also allow to analyse several lines at once. Using this Multi-PV feature, the user can see the second or third (etcetera) best continuations. The best line is always on top and highlighted. If an engine allows for Multi-PV analysis, the spin box can be used to set the number of principal variations shown. In this case, instead of the calculation history, only the resulting principal lines are shown. The spin box is disabled if an engine does offer this feature.

Extra Information

At the bottom is some additional technical info. If this is hidden, it can been seen by pressing the Engine Info button.

Depth: the search depth already reached by the engines calculations (in half moves).
Nodes: the number of positions analyzed for the current result (and the number of positions per second).
Time: the amount of time spent for the current analysis.

Additional information includes the number of tablebase hits, a more exact number of nodes analyzed per second, the watermark of the engines hash and the current CPU load.


Annotating Games

Games can be automatically analyzed using the Annotate Button (in the Analysis Engine toolbar). This feature adds Scores, Comments, Informants, Bestlines to games.

There is also a new option to add Missed Mates. This adds all missed and shorter mates which are at least a few ply shorter of the 'Depth per move' setting (as at higher ply, the engine's results are not too reliable). Additionally, the added line may not be complete - ie. it may not end in mate. This is due to the engine reporting "Mate in n", but not actually giving the whole line/PV, which is a common UCI engine oddity.

The Annotate button is only shown in the first engine window.

After configuring the options and pressing OK, Autoplay Mode is enabled, tree updating is disabled, and the engine starts its analysis. A variation and/or score is automatically added for each position as the engine processes the game. Only positions from the current one until the end of the game are annotated, so you can skip annotation of opening moves by moving to a mid-game position before starting. Pressing the Annotate Button a second time cancels annotation.


Informant values are also configurable.


The Training Button (only available for engines 1 and 2) allows one to play against the engine. The engine moves first (from the current position) and may be stopped by pressing the button again. The time for each move is fixed, and analysis results are not updated while training mode is on.

Configuring Engines

The Tools--> Analysis Engines widget is where you can Configure, Add, and Start Chess Engines.

Scid vs. PC installs a few engines by default. To install new ones you'll need to know the program's Command, any Parameters it takes, whether it is uses the UCI or Xboard protocol, and also the Directory it should be run in. This sounds complicated, but is not too hard :-) Sticking points are likely to be the choice of which directory to use, and whether it's UCI or not.


Many engines require an initialization or opening book file in their start directory to run properly. Other engines, like Crafty and Phalanx, write log files to the directory they start in, so write access will be required. If the directory setting for an engine is ".", Scid will just start the engine in the current directory.

If an engine fails to start, try changing its directory setting. To avoid engines creating log files in many different directories, I recommend trying the ~/.scidvspc button. Engines necessitating opening books and/or .ini files, will need a directory of their own however.

UCI and Xboard (also known as Winboard) are two protocols for communicating with engines, and it is necessary to set this flag accordingly. If you're not sure, try one then the other, as nothing will break. Some chess engines support both formats.

If an engine needs additional parameters for startup (e.g. a specific opening book) they can be specified in the Parameters field. ... Please refer to the engines documentation.

Webpage allows you to set the engines homepage. This comes in handy to check for updates e.g. or to have a look at recent developments. Pressing the Open... button will open this page in the web browser.

After the engine is configured, Scid vs PC will give it a Date stamp, according to the executable's modification time.

UCI Configuration Options

UCI Engines can be configured by pressing or Configure in the Edit Window, whence a dialog with the engines parameters will be shown. (Gilles - where is the help section :|). Scid generally ignores options of the format UCI_* , according to the UCI standard. Additionally, Chess960 support is not enabled because implementation is very problematic.

Debugging Engine Crashes

If an engine fails to start, or crashes, one may examine its log file. These are kept in the Scidvspc's log directory and can be viewed via the button in the engine configuration widget. The Log Size is the max number of lines in the log. Setting it to zero disables logging altogether.