EGBB path in common engine

[Gábor Szots]

Under common engine there is a box for the EGGBB path, only I don't know what type of EGBB can be used here. Nalimov, Sorpio, Gaviota, other? And will WB use them automatically for all engines or only if the engine supports them?

[H.G.Muller]

Now I hope I tell this right, because it was some time ago I did this:

The 'EGTB Path' option in the Common Engine dialog originally (i.e. in Winboard_x) was used only for UCI engines, passed along to Polyglot as Nalimov Path (as at that time there were no other formats supported by UCI). But later we implemented the 'egtpath' command in WB protocol, and a WinBoard option -egtFormats to control its use. That option can specify paths for all formats available on the machine (like "nalimov:D:\egtb,scorpio:D:\egbb"). The engine (or Polyglot) then tells WinBoard what formats it can handle, through the 'egt' feature (e.g. feature egt="scorpio"), and WinBoard will send it the paths for those formats (if available on the machine) in separete 'egtpath' commands.

What you write in the Common Engine EGTB Path field will be taken as the new value for -egtFormats when it contains a name of more than one character followed by a colon (like "nalimov:..."). One character before a colon would be considered a Windows disk-drive name, and if the string starts with that (or contains no colon at all) it will be considered the new value of -defaultPathEGTB, which is the Nalimov path. -defaultPathEGTB is really a deprecated option (the new method of specifying a Nalimov PATH being /egtFormats="nalimov:PATH"), but for backward compatibility, when it is defined as a non-empty string, the Nalimov path will be taken from that option rather than the -egtFormats option. (But only for Nalimov; all other formats can only come from -egtFormats.)

[Gábor Szots]

Thank you, it is clear now (or so I feel).

Best regards,