by H.G.Muller » 15 Aug 2020, 09:16
When you started WinBoard with an engine, you could simply select Machine White / Machine Black / Two Machines from the Mode menu. When you started in Game Viewer mode, you would first have to load an engine through the Load 1st Engine dialog (and if you want to use Two Machines also a 2nd engine).
Note that when you edit a position, you would also have to indicate the side to move. Otherwise that would just stay what it was before you started editing. You can set a player on move by clicking on the clock for that player above the board. WinBoard indicates the current side to move by making its clock white letters on black background.
You cannot set the computer to play a side that is not currently on move. You would first have to click Edit Game, play your own move, and then set the engine to play. For 'trying out your own ideas' it would seem more natural to switch the engine to analyze mode than to actually play against it. You can do that irrespective of who is on move, as in analyze mode the engine will think for both players, but leave it to you to move for both players.