From the Introduction to this page: "...Such 10x10 games, often called decimal chess, have been the holy grail of game designers for ages. Many scholars felt that the move to a 10x10 board would be the next logical step in the chess's continuing evolution..."

I've been recently thinking about this matter (whether the 'next chess' ought to be played using a 10x10 square board), not for the first time. My initial thought was that 10x10 is the biggest square board one could nicely fit on a coffeetable, with squares and pieces of reasonable size (most people I thought would prefer a square board over a rectangular one for aesthetic reasons). Such a board could also accomodate a much larger number of pieces, say up to 60 (lately I've wondered if that's too many pieces to store conveniently in a box or bag, also with the slight extra time used to put away or take out every time too - plus more noise made doing so, at a club or event, all arguably a slight irritation). I have also read that at least some chess grandmasters think 10x10 may be too overwhelming, say for calculating purposes in a game, however.

Also, unless both sides armies are placed only on the first two ranks, which restricts the maximum size of an army to 20 units, the pleasing possibilities of smothered and back-rank mates would often be lost for a variant, I'd assume (at least if FIDE pawns and pieces are included in the setup, and in a pleasing way). I also thought about 9x9 or 11x11 boards, but they are awkward if two bishops (or another colour-bound piece pair) are desired to be included - other than that, shogi and possibly wa shogi (maybe just with the use of drops) are nice chess variants that just might smoothly take over from chess as the next chess, if only western eyes might like the odd physical pieces (and maybe their movements) more, perhaps.

All that led me to revisit rectangular boards as perhaps an ideal next step for finding a variant surpassing the domination of (western) chess. 12x8 is already a little too wide (see what I alluded to in my second paragraph), and it makes castling take much longer, unless a new form of castling is introduced, which may not prove to be popular (I made such an attempt with my own 12x8 Wide Chess variant). Variants that are 11x8 are awkward, in that bishops to be symmetrically placed in a pleasing way for most people need to be on the same coloured squares in the setup, with some sort of bishop's adjustment/conversion rule to allow one bishop to go to the other colour for the duration of a game, a rule which so far hasn't seemed to be extremely popular in Game Courier play for any number of board sizes or shapes. Variants that are 9x8 would only allow for one more piece to be added to the first rank of an army, if chess tradition is respected at least in so far as pawns and a 50% pieces to empty squares ratio is used.

That left me with 10x8 boards (assuming hexagonal or circular boards, for example, could never prove popular enough due to the oddities caused by their geometry, alone).. If I respect having pawns and a 50% pieces to empty cells ratio for a setup (maybe awkward for 10x10 variants), that allows for (just) two more pieces to be added per side. I'm not sure that's enough that such a variant's opening theory would not be exhausted for a very long time, as I imagine would be desired by many, if a random setup like chess960 were not used (chess960 would be extremely excellent for this purpose, except a lot of its setups are a bit awkward or advantegous to White compared to chess, and that might be true of random 10x8 variant setups too, and forget about setting up the pieces on your coffeetable, in a store or in a movie, with no fixed setup).

Having re-thought about all this, I'm once again thinking 10x10 square boards are the most promising way of the future for chess lovers, as John Brown stated above, with little things like possibly lost smothered and bank-rank mates being damned. Does anyone have any thoughts on any of this?