Comments/Ratings for a Single Item

Having analysed this variant thoroughly I have been torn between the
ratings Good and Average. In the end I plumped for Good as it does seem a
good game, but mostly by accident and despite the presentation. Sorry if
this seems faint praise.
	The first thing to notice is that that 'pentagons' are really hexagons
with one corner flattened. Where a cell is surrounded it is by 6, not 5,
others. The board as a whole resolves itself into a hex board of
Glinsky/McCooey orientation, irregular in shape but symmetric about a
midline. The number of cells per file are, from left to right: 1, 6, 7, 8,
7, 8, 7, 2.
	This of course has an impact on the pieces. The Pawn analogue is the same
as Glinsky's. The Elephant analogue is bound to 1 in 3 cells, but the
Knight analogue to still less, 1 in 4, being in fact a Dabbaba. This is
the reverse of the analogy in my own variant Hex Dabbaba Qi! Each player
has a Dabbaba bound to each of the two bindings forming together the files
with even numbers of cells - binding all to identical numbers of cells. Yet
there is no mention of this feature on the page!
	On the whole this is a good version of Chaturanga, but a good hexagonal
rather than pentagonal one. It inspires me to wonder whether I can do one
as good on a more regular-shaped board (a Chaturanga counterpart to HDQ) -
and also to how pieces would move on a board of genuine pentagons.

But I re-read Charles Gilman's comment and I see that he is also correct in his observation because in looking at a cell's mechanics it does function as a hexagon. Bending out the long edge with a point where the line meets at the center will give you the hexagon in appearance (without the bend it remains a hexagon in function. R Wayne Schmittberger had demonstrated how circular cells can also end up making hexagons... Anyway, it is a clever idea.

The game looks very nice but I'd need to play it before rating it.

The piece graphics are from a Chinese Chess program I've seen. And so I think that program should be credited for the use of their graphics.

In closing, the board is very clever and the piece movements should allow for an interesting game.

Thank you all for taking the time to examine and comment on Penturanga.

Charles, I'm not sure exactly what you mean by 'despite the presentation', but I admit it to be somewhat sparse. In order to meet the competition deadline I published the basic description without a supporting Notes section. I hope to add this and publish a zrf shortly.
Also , while I agree with you that that the board is topologically equivalent to the hex-board you describe, this does not mean the pentagons are anything else other than pentagons - the number of surrounding cells is irrelevant as can be seen by the usual square board where each cell is surrounded by 8 others. Topological equivalence also does not lead to equivalence in game-mechanics. In short it is my opinion that Penturanga is indeed truly pentagonal.

Gary, the piece graphics were derived from a Chinese set published on this site. Full accreditation will be given in the Notes.

'Topological equivalence also does not lead to equivalence in
game-mechanics.'

Oh yes it does.

'In short it is my opinion that Penturanga is indeed truly pentagonal.'

Regardless of your opinion, the fact remains that Penturanga is just a
funny-looking hexagonal chess variant.

Despite the gruff tone of my last comment, I found some of Mr. Neatham's
other games to be good efforts: Fool's Hex Chess, A9, TriMac HexChess,
and Penguins and Predators.

'Topological equivalence also does not lead to equivalence in game-mechanics.'

Create a piece whose move is defined as:

a series of steps away from the starting cell exiting each cell via a short side.

Such a piece can be moved on the Penturanga board but not on the topologically equivalent hex-board.

'...the fact remains that Penturanga is just a funny-looking hexagonal chess variant.'

I'm afraid that is not a fact, it is, like mine, just an opinion - so may we just agree to differ?

Cheers
Graeme

Your example piece is a red herring.

My example piece may well be called a herring, red or otherwise, but it illustrates that topological equivalence, though necessary, is not sufficient for game equivalence. That having been said, I agree that for the pieces actually used in Penturanga there is game equivalence between the pentagonal and the hexagonal boards.

... but this is a mathematical problem with a definitive answer.

Exactly! A square has 4 sides, a hexagon has 6 sides, a triangle 3 sides, and a pentagon 5 sides. A board with 6-sided cells is termed hexagonal, so surely it is correct to term a board with 5-sided cells pentagonal?

Cheers
Graeme

It does appear that this game visually lends itself to different kinds of
movements, even if it can be seen as an equivelent to a hexagonal board. 
For instance a rook piece may alternate between one and two paths to reach
a destination cell.

    _____
 / \     / \
| - \_-_/ X |
| - / - \   |
 \ /_____\ /

In the lame ASCII diagram I have just given, you can see how a rook on the
far left pentagon can take two routes to reach cell X (the hyphens
representing arrows outlining the two paths).  If I had the
patience to produce another set of pentagons, you could see how both paths
merge on X, but could then split and merge over and over again.  Though
this movement is equally possible on a hex grid, it is far more visually
appealing on Neatham's Pentagonal grid.  I think that it could even be
interesting to allow the rook to change which path it takes whenever
desired, making it a difficult piece to block.  I believe further
exploration of Penturanga's idea could be quite interesting

However...

Perhaps a better pentagonal grid would have been a more pure one in
nature, like the one shown here:

http://gwydir.demon.co.uk/jo/tess/pent.htm

This grid only allows its pentagons to come in contact edge-to-edge five
times.  This may be the more pure grid that some here are seeking.

Graeme, sorry for contacting you this way, but I've had some computer issues recently, and I currently cannot send emails, though I can receive them.

Do you have board templates for this game and your other contest entries? If you do, would you please email them to me [see my person info onsite], as I'm lazy enough [or too pressed for time right now, if you prefer] not to want to make the boards tonight or tomorrow morning, for purposes of judging your entries. Jeremy and I hope to look at them this weekend, as we've already started work on the entries. We got together a bit last weekend and looked at 2 games [not yours], and plan to get together after this weekend at least once more in January to continue the difficult work of playing games to see which ones are best; rough, but somebody's gotta do it. If you don't, no big problem. By next month, we can make the boards, and look at your stuff then. Either way, thanks for your attention to this. Joe

Joe,
just sent you an email.

Cheers
Graeme

I like this game very much, but I would not have limited the pawn promotion
so much had I created it. The first thing I would do if I were
transliterating Chaturanga/Shatranj to a quasi-pentagonal board would be
to keep the basic pawn promotion rule from the original game intact
instead of discarding it altogether and then add the piece that starts on
or directly in front of that cell to the promotion options. In the event
that a Pawn landed where the opponent's Adviser/Counselor started, it
would be able to promote to any piece other than the king. That gripe
aside, the game is a very good quasi-pentagonal version of chess. However,
there is no rating between Good and Excellent and I could not really give
an Excellent rating the game is not completely faithful to its historical
original with regards to Pawn promotion.
P.S. I am referring to the board as quasi-pentagonal because a true
pentagonal board is a tessellation of pentagons that does not involve
pushing small groups of them together into shapes other than pentagons and
I did not call it hexagonal as that would imply that it was nothing more
than a hexagonal grid.

Speaking of which, is there any interest in my inventing a variant using an alternate tessellation. I have an idea that has been bouncing around my head for over a decade which I should make a variant out of, but only if people would be interested in looking at it.

- Sam

Would you be open to me modifying your Zillions' file to have, in the variant pop-down-list, some ideas suggested here:

• Free pawn promotion
• An opening setup where each side gets three elephants
• Both of the above ideas

- Sam

Sam Trenholme wrote:
'Would you be open to me modifying your Zillions' file ...'

Please feel free to modify the file as you wish.

I think Game Courier only supports square or hex boards though it may be possible to upload a custom graphic.

John, you're right that modifying the board that way gives an extra rear rank board location for each side to place a third bishop, and, being 3 pentagons per hexagon, this also gives a 45 position board, fitting the contest theme. I have 2 objections to that, however, The first is aesthetic. The board will be a parallelogram, with corner angles of 60 and 120. It doesn't look right, and it's annoying to play at an angle like that - you want to grab the board [right off the screen] and straighten it out. The second objection is concerned with playability. 

Take a look at both of the boards. The center row of one is 3 hexes - 9 pentagons - across. The other is 4 hexes, and 12 playable spots in the middle of the board. The 3 extra spots in the center on Graeme's board are the one that was lost going from 46 to 45, and the two that the extra elephants occupy, now in the back rows. Does this make much of a difference?

How many pawns does it take to make a solid wall completely across the board? In Graeme's game, in the setup, the 6 pawns cover the 3 hex board 'row' they're on, occupying 2 of the 3 pentagons in each hexagon. To do the same in the middle of Graeme's, you'd need 8 pawns, which the game doesn't have. The middle of Graeme's board cannot be clogged by pawns. On the 45 position board, it only takes 5 pawns to clog [form an unbroken line from side to side] the board. There are 6 pawns in the game. 

In general, especially with all other things being equal, I believe that the narrower the front, the easier it is to jam it up with pieces and kill zones, so the more drawish it will be. Further, Graeme's board is very roughly circular [at least in intent], giving maximum room for maneuver in the center of the board. This game won the contest because it 'plays big'. It feels like the 64 square game, even though it's on a much smaller board. It also doesn't feel crowded, thought the starting piece density is ~60%. Narrowing the board from Graeme's 6-8 pentagons down to 5 pentagons, losing one spot and adding two pieces would likely create a clog in the middle of the board, in my opinion.