Tremendous Chess. In the literal and figurative sense.

Epic Chess was just the beginning. Götterdämmerung was a test of the activity of pieces in the limited space of a standard 8x8 board. And now the evolution of my thought of such initial setups has reached its climax.

Let me introduce you to Tremendous Chess.

In the literal sense, it is very great in amount, scale and intensity chess.

I can anticipate your reaction: "What the ..." But let me take some more of your precious time to show you the beauty of the game.
Unlike most chess variants on a big or really big board, there are no fairy chess pieces here that are designed to overwhelm the vast expanse of the chessboard with their intricate maneuvers. I have repeatedly said that standard chess pieces are self-sufficient and their potential can be realized on boards of any size. The only question is their number and the pattern of their initial placement on the chessboard. Ok, we can talk about this endlessly, and my task is to introduce you to something amazing and unique.

Rules of the game.

Tremendous Chess is a large chess variant that is played on a 16×16 chessboard with 112 pieces per player and the starting position shown above.
This chess variant on a really big board is played according to the rules of progressive chess, i.e. players, rather than just making one move per turn, play progressively longer series of moves. The game starts with White making one move, then Black makes two consecutive moves, White replies with three, Black makes four and so on. 
Series are continuous and there are no restrictions on individual moves in a series except for the following:
- a check may only be given on the last move of a full series (for example, on move six, a check can only be given on the sixth move), while checkmate can be delivered on any move of the current series. If the only way to escape a check is to give check on the first move of the series, then the game is lost by the player in check by "progressive checkmate".
- if at any stage a player has no legal moves but is not in check, the game is a draw by progressive stalemate.

A check must be escaped from on the first move of a series—if this cannot be done, it is checkmate and the game is lost.

It is well known that Progressive Chess, like no other, develops combinational vision and contributes to the development of strategic thinking skills and long-term planning.
However, limited to a standard chessboard, such chess cannot fully reveal the beauty and depth of the game's unit synergy. Within the same framework, human thought becomes cramped and uncomfortable. We need more opportunities and freedom of action. And so the idea of creating Tremendous Chess matured.

If we consider the initial arrangement of Tremendous Chess from the point of view of the coordinated action of all chess pieces on the board, then the consistent introduction of these pieces with different specific gravity into the game makes it possible to achieve a harmonious duel, a fruitful opposition of one creative thought to another.

As an example, let's look at one of the very first games played in Tremendous Chess.

Note that Progressive Chess, like Orthodox Chess, has an algebraic notation. However, the numbering of moves is handled slightly differently. Rather than one White and one Black move being given under each move number (leading to notation in orthodox chess like 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6), each turn by each player is given its own move number (leading to notation in progressive chess like 1.e4 2.e5 Nf6 3.Bc4 Qh5 Qxf7#). In this way, the move number is equal to the number of moves in a series available to a player on that turn.(Progressive chess)

1. Nce8

2. Nfxe8 Nxf6

3. Bexf6 Ngf9 Nxd10

4. Nfxd10 Ne8 Nxf6 Nxg4

5. Rxg4 Nde9 Nxd11 Nxe13 Nxg14+

6. Rgxg14 Nhi8 Nxj6 Nxh5 Nxi3 Nxh1

Knights, like knives through butter, pass through the orderly ranks of the enemy army, leaving gaps in the defense.

7. Kxh1 Bxj10 Bxk11 Bxj12 Bxi13 Bxh14 Bxf16

8. Qexf16 Ned8 Nxc6 Nxb4 Nxc2 Nxe1 Nxf3 Nxg1

9. Qxg1 Nkj9 Nxi11 Nxj13 Nxi15 Nxk16 Nxl14 Nxm16 Nxk15

10. Qlxk15 Bxc3 Bxb2 Bxc1 Bxd2 Bxe3 Bxf2 Bxg1 Bxh2 Bxf4

Black gloriously beat up White's defense and a mating attack is just around the corner. Whites do not yet notice the threat looming over them and continue to harvest on the Black half.

11. Ngxf4 Bf6 Bk7 Bxn10 Bxm11 Bxk13 Bxm13 Bxk15 Bxj16 Bxg13 Bxh12

White continues to ignore black's threats, plus he makes a couple of stupid moves, losing important tempos. Now looking at the position above, can you, as Black, checkmate White in a series of 12 moves? In fact, Black checkmates already on the 11th move.

The White King's position is vulnerable and Black delivers a coup de grâce.

12. Nge10 Nf8 Nxh7 Ni5 Nxj3 Bxb7 Bxd5 Bxe4 Rxg4 Rxg2 Rg1#

Impressive, isn't it?

Tremendous Chess is a challenge for any chess player, especially for those who are fond of Progressive chess or just want to try something new, get a "thrill". I know many masters and "experts" of chess are afraid of new variants of chess like hell. Partly because they are afraid of the unknown, partly because without their faithful "helpers" of chess engines, they become vulnerable to new challenges or trials. 
Conduct an experiment - invite your friend, who plays better than you, to solve the following Tremendous chess problem:

Black checkmates White in a series of 12 moves. Since your friend is well versed in chess, he or she should be familiar with Progressive chess, and if not, he or she will quickly figure out what is required of him or her to do. 
I wonder how long it will take a FIDE Master to solve such a problem? Most likely, both a FIDE Master and your friend will send you to hell. Because with all the obvious similarities between standard chess and what happens on the Tremendous Chess board, we have chess of a completely different order, where the effectiveness of each individual chess piece is enhanced by interaction with other pieces and a combination of factors inherent in Progressive chess. Before us is a system with many elements that are in relationships and connections with each other, which forms a certain integrity, unity, significantly different from regular chess.
What about chess engines? If they existed for such a chess variant, then they could well achieve the final goal, but despite all their productivity, chess engines will not be able to correctly evaluate the positions that arise in Tremendous Chess.
As we know, in practice, due to the combinatorial explosion, no computer is able to calculate the complete game tree (exhaustive analysis in endgame databases is a separate case). Therefore, the programs work in the so-called Shannon model - they use a truncated game tree and an approximate estimate based on various heuristics. But even in this case, with all the scale of Tremendous Chess, all engines are initially doomed to failure.

I hope you appreciate the beauty of playing Tremendous Chess. Getting the size of such a board is not so difficult. It is enough to connect four standard chess boards into a solid square. Yes, you still need 16 chess sets for a full game...But can the pleasure derived from the game be measured by material values?

Oh yes, I almost forgot. The solution to the proposed puzzle. Just don't show it to the FIDE Master ;)

Here are the 12 moves:

Nj9 Nxi7 Nxj5 Nxi3 Nxg4 Nxi5

Nkl8

Blh8 Bxl4 Bxk3

Rxk4

Nj3#

If it is difficult for you to imagine the movement of the pieces on the board, then here is a schematic representation of the checkmate.