As in the old Mephisto Polgar days you can now play elo-rated games but much more advanced. ProDeo 2.4 will play at you wished strength and you can gain or lose elo points. View the below screenshots to get an impression.
Click on a picture to enlarge.
The ELO range of the program is between 1000-3400. You can't go higher. You can't go lower.
If the engine is set to an ELO of 1500 (the default setting) really plays as an 1500 ELO rated player in real life has to be seen. The same counts for any other ELO setting. Time will tell and will depend on user feedback, for instance using the below Facebook plug-in.
As you will notice there are no main variations which could help you what to play. As in real life you are on your own.
This ProDeo version will only work properly with Arena.
On lower ELO level ProDeo will be quite tolerant, it will reward a win much higher than a loss, you even gain ELO points for a draw. The opposite is also true, on true high ELO ratings ProDeo becomes less and less generous. The capriciousness is represented in the following table, ELO levels varying from 1000-3400, displayed as 10-34.
Prodeo 2.4 will exclusively run under Arena (pre-installed) and the first time you start Arena it will show a default rating of 1500 ELO. When this is way out of line with your own ELO edit the file player.txt with a text editor.
There are a couple of annoyances because of the limitations an engine will face programming what actually is an interface (GUI) feature. Therefore while playing keep in mind the following rules:
As in normal chess there is no such a thing as a Take Back. When you do you lose instantly. Just avoid that button. That might need some practice as I can tell from experience during development and testing this particular feature.
The New Game button is another story. Besides starting a new game it will also function as your resignation. Of course, the logical exceptions are when the program has resigned already or the game already ended (Checkmate, Draw or Time Forfeit).
A little annoyance will occur in case you resign (by pressing the new game button) Arena will start a new game but does not yet communicate that with ProDeo and thus the ELO update does not appear in the (black) ProDeo window immediately. This will happen with the next move.
It's expected this first try is not without a few glitches here and there due to the nature of the feature. Interfaces (GUI's) don't communicate the many things the engine needs (no checkmate, not the various draw types, no clocks etc.) and it has been quite a job to get at least one Interface (Arena was the most suitable) to work with the ELO feature. Hence the beta status. There might be some unexpected quirks showing up. Please report them.