I am annoyed to see it classified as such. Connect four is a classic game that has been around for hundreds of years; Captain Cook is said to have played it on his voyages.

Maybe the 8x8 board is new, but I do not think that that is enough of a change to make it a new game. Why do so many turn-based sites (littlegolem, itsyourturn, goldtoken, brainking) have the 8x8 board anyway?

This site used to have a 7x6 board. It was changed a couple of years ago at the request of some of the players, due to the fact that the 7x6 board has been solved. Player 1 has a sure win. The 8x8 board has not been solved for either player, to my knowledge anyway.

See this thread for the discussion about the board size.

I see I forgot to include Pocket-Monkey on the list of sites with 8x8 boards.

Yes, I know that 7x6 has been solved, but 8x8 is not the only viable alternative, so I wonder why so many sites use it. I guess that everywhere is imitating IYT. By the way, some strong players think that player 2 has a sure win on the 8x8 board. Hopefully it will someday be solved as well.

I don't think it's a matter of immitation. Everyone could use a size of say 20x25 and it would be surely not solved for years (or centuries) to come. But how long would games last at this sizes? There has to be a balance between reasonable game duration and non-solvability. I suppose 8x8 or 7x9 gives that balance at this moment.

8x8 is a nice size. If you don't have an even number of rows, you cannot employ most of the parity strategies that are applicable in the 7x6 game. 7x8 is possible I guess, but all diagonal and horizontal threats have to go through the central column, and I expect most games between strong players would be over pretty quickly. 8x8 is about right, but having more columns would create a very interesting expert game in my opinion. 10 columns by 8 rows, or even 10 columns by 6 rows would be quite difficult! There are not very many possibilities in the opening in 4IR (when you take into account transpositions, reflections, and poor quality moves). Adding more rows doesn't do much for the game except slow it down.

I have played more than a thousand games on a 7x7 board, so I think that an odd number of rows results in a reasonable game. The differences between boards of even and odd heights are sometimes confusing, though. For example, player 2's even threat beats player 1's odd threat on a board of odd height (assuming the threats are in different columns).

I've heard that 10 columns by 8 rows has been done already.

Even so, I'm sure that you would agree that even-row games all use similar strategies that are quite different from odd-row game strategies. I haven't played any stacktris, but that game has another angle to the parity strategy (parity flips every time a row is removed).

Yes, absolutely I agree that even-row games all use similar strategies that are quite different from odd-row game strategies. What I do not see is that even-row games are better than odd-row games.

I have played a few games of stacktris (if I know what you're refering to, what site has it with that name?) as well as 4x4 and one anti game. However, I haven't analyzed them much so I won't comment on them.

Anyway, do you agree that connect four on any size of board is still connect four? Or do you classify some sizes as variant games, in the same class as stacktris?