Board Game Arena

I thought BGA did not support any form of solo games. But on the filters under "Games", the first option is "Solo" under "Number of Players".
I recognize some of these games that I do own, and they do have a one-person version in the hard copy, so this seems like a real setting. Does it just mean "If you bought a paper copy you could play this game solo, but not here on BGA"? Is it just a mistake in the programming?

You can play these games Solo on BGA! You fist need to change to Training mode and then you can adjust the number of players to 1 in the setting. Then it is a Solo game.
If there is a special Solo variant for a game, it is however not 100% clear if the Solo variant was implemented or just the normal variant. You may need to adjust more settings or simply try it out. You can't get penalties in Solo games.

There are great solo implementations of games on the site and I'd heartily recommend checking them out. Sadly some popular games which have solo modes do not have them implemented on the site but that's the nature of BGA. I've personally enjoyed plenty of quick solo games of Bandido.

Ah, thanks for letting me know! I'll check it out.