Comments by nelk114

As for pieces that can only do slide‐then‐step and not the reverse, the only one that comes to mind in a game is the Transcendental Prelate.

While on its own the original diagram on this page was a bit obscure, in conjunction with Fergus' circular diagrams it really clarifies the rationale behind Nadvorney's interpretation of the diagonal move; a bit of thought also reveals why Miller's reasoning in keeping the bishop on its own colour is flawed: if the bishop stays on its own colour you would expect a rook stepping over the pole to change colour as it does on a normal square‐cell board, whereas here (or on any spherical/Klein‐bottle‐shaped board with a multiple of four files) it doesn't. On e.g. a 10‐file board, Miller's reasoning would line up with Nadvorney's.

As for Chess on the Dot, the change in the diagonal's handedness at the poles also keeps it on one colour (on a board of this parity), but isn't stirctly necessary for a closed loop: Nadvorney's version (as can be seen on its diagram) does it just as well, and even Miller's manages, albeit via a much more circuitous route.

Fwiw, here's the original diagram as salvaged from the Internet Archive:

c7  d7  e7  f7  g7  h7  a7  b7  c7  d7  e7  f7
c8  d8  e8  f8  g8  h8  a8  b8  c8  d8  e8  f8
g8  h8  a8  b8  c8  d8  e8  f8  g8  h8  a8  b8
g7  h7  a7  b7  c7  d7  e7  f7  g7  h7  a7  b7
g6  h6  a6  b6  c6  d6  e6  f6  g6  h6  a6  b6
g5  h5  a5  b5  c5  d5  e5  f5  g5  h5  a5  b5
g4  h4  a4  b4  c4  d4  e4  f4  g4  h4  a4  b4
g3  h3  a3  b3  c3  d3  e3  f3  g3  h3  a3  b3
g2  h2  a2  b2  c2  d2  e2  f2  g2  h2  a2  b2
g1  h1  a1  b1  c1  d1  e1  f1  g1  h1  a1  b1
c1  d1  e1  f1  g1  h1  a1  b1  c1  d1  e1  f1
c2  d2  e2  f2  g2  h2  a2  b2  c2  d2  e2  f2 

Charles Gilman called these Zephyr and Lama respectively, though by his description they cannot make the one‐step move that I'm not sure whether you're including. The latter also turns up as an Osprey in Expanded Chess

The Princess' diagram disagrees with the text in omitting sideways moves

Ok so you are indeed including the 1‐step move among the movement possibilities — I suppose your ‘2.manticore’ is different enough from a lame/stepping/blockable osprey/lama (and mutatis mutandis for the ‘2.gryphon’) to merit a different name… maybe. If it's not being distinguished from a ‘true’ osprey/zephyr in a single game I'd be tempted to leave that name as is, though avoiding going too near overlexicalisation is a personal preference.

If the distinction does need to be made within a game (at which point the tradeoff changes imo), then ‘2.manticore’(/‘2.griffon’) is probably fine, if perhaps closer to the (presumably also present in a game featuring both of these) actual manticore/griffin than might be desirable, though I'm not really one to ask for original name suggestions (and M&B13 is apparently lacking names for lama/rook and zephyr/bishop compound with which we could (ab)use M&B8's ‘‐lander’ suffix). Perhaps a name based on lama/zephyr/osprey/ostrich/whatever you want to call them would be more apt? ‘Running Osprey’ isn't altogether without a ring to it…

Does XBetza allow defining pieces that capture by stopping in the square just before the captured piece?

yamcfyambK comes close to defining a Queen that does that, aka Rococo's Advancer; it is, however, what Charles Gilman called a ‘Strict’ advancer, in that it also can't approach a friendly piece (as doing so would capture it), as well as (as a byproduct of the implementation) being unable to approach the edge once it's left it. Adding mQ would lift those restrictions at the expense of making the capture upon advance optional. Idk if it's possible to do better without extending the notation though

Another question I have is, does 0 have any meaning when used as a piece's range? If not, perhaps it could be used to indicate that a piece must move as far as possible in whichever direction it goes.

Afaict (istr it was declared explicilty at some point though idr where) 0 corresponds to unlimited range. gabQ handles going as far as possible provided there's a piece in the way, but is subject to the same edge case(!) as the advancer wrt the boundaries of the board — again I doubt it's possible to contrive a way around that without dedicated extensions

The chance of rolling a double is 1/36. https://stackoverflow.com/questions/32313428/understanding-the-probability-of-a-double-six-if-i-roll-two-dice

The chance of rolling any given double (e.g., as in your link, a double 6) is indeed 1∕36. There are, however, six doubles to choose from, so the total probability is in fact 1∕6 of rolling any double.

The chance of rolling a single is 1/6 ⁓ but two dice thence double the likelihood of instances to 1/3

Alas, adding probabilities does not work that way. In effect you've counted the outcome of a double twice. The chance of rolling at least one of a given number with 2 dice is, in fact, 1−(1−1∕6)²=11∕36.

Back‐of‐the‐envelope translation:

este ajedrez tiene un tablero modificado de 73 casillas .

This chess [variant] has a modified board of 73 squares.

las piezas adicionales a las convencionales son :

The pieces in addition to the conventional ones are:

un canciller : torre + caballo .

A Chancellor: Rook+Knight

el omega que mueve dos en diagonal y salta a la segunda casilla en diagonal ademas ,puede saltar a la 2da. casilla en ortogonal con una pieza de por medio.

The Omega which moves 2 diagonally and jumps to the seconddiagonal square; additionally it can jump to the 2nd square orthogonally with a piece in between.

los peones se llaman columnas y pueden tambien mover una casilla en diagonal hacia atras en ambas direcciones si estas estan desocupadas.

Pawns are called Columns and can also move one square diagonally backwards in either direction if these are vacant

el rey es un Emperador : rey + caballo .

The king is an Emperor: King+Knight

reglas especiales :

Special Rules:

_se mueven dos fichas por turno pero solo se puede comer una vez por turno.

• Two pieces are moved per turn but only one capture may be made per turn

_una ficha no se puede mover dos veces en un solo turno..

• A piece cannot move twice in one turn

_por cada 4 piezas que un bando atrape obliga en el siguiente turno de su adversario a que reinicie una de las piezas que haya capturado como aliada.

• For every four pieces captures by a side, his opponent is obliged on his next turn to reintroduce one of the pieces he has captured on his side

_las piezas iniciadas comienzan en cualquier casilla de la 1era. fila de su bando.

• [Re‐]introduced pieces begin on any square on the 1st file of their side

_cuando un rey está en jaque puede salir de un mate intercambiando 2 piezas de jerarquia () por un cambio de posición hacia una casilla que esté libre. (es opcional).

• When a king [i.e. an emperor?] is in check he can escape mate by exchanging two pieces of hierarchy () [sic] for a change of position to an empty space (this is optional)

_el atacante escoge una pieza y la inicia como aliada , el atacado escoge la otra pieza..

• The attacker chooses a piece and introduces it on his side; the attackee selects the other piece

As to the “two” corner squares, removing two squares from each corner of a 9×9 board does in fact leave 73 squares, though whether the second square is vertically or horizontally adjacent to the square in the corner remains unclear. Presumably the promised diagram will clarify.

It looks as if it might mean bringing one's king to a space adjacent to the opponent's)? Would be not unlike Bachelor Chess (and a number of Gilman's) in that respect. Hence the commment about kings meeting on “their” — i.e. ‘one's own’ — half of the board, the case of 4th/5th ranks, and the note about “approaching” the opposing king.

Also the fifth paragraph remains given twice

the players start with […] a queen and a king and 8 pawns on their secind rank

All standard chess pieces except the king

The king isn't royal

These statements contradict each other. How can the player start with a king that's not in the game, and how can said king be non‐royal?

Also the rules regarding pawns are a bit unclear — am I right in inferring that a pawn effectively demotes upon reaching the last rank while adding a new ‘pawn’ (which can still move as a queen) into the pocket? thereby making the pawns a potentially infinite source of new pieces?

when playing the game one is generally attempting to achieve a particular double

Perhaps, but if that's what you meant it might be worth being clearer about that; the way it's phrased aþm suggests that the probability of being able to make any Séj‐dice capturing move (assuming availability of pieces to capture) is 1∕3+1∕36=13∕36, which doesn't really make sense (not least, that'd be likelier than merely being able to move even if the 1∕3 figure were correct). The actual probability is in fact, as dax00 said, 11∕36(=chance of matching the last piece to move)×1∕6(=chance of a double)=11∕216. The chance of any given piece being able to capture is 1∕6 of that again, i.e. 11∕1296.

since the fraction 11∕36 is almost a third, doesn't that in effect equate to 1∕3?

Well 1∕3=12∕36, so… no? It's close, sure, but still an 8.33% difference — if you consider that trivial enough to be discounted fine, but don't expect everyone (especially those of us with a mathematical inclination) to agree.

There is a 66.6% chance that, because each turn the dice MUST match the opponent's piece, thence the game will continue as regular Classical Chess

I also just noticed this remark; even aside from the percentage being wrong — the chance that a given turn will be ‘normal’ is 25∕36=69.44% — it's not clear whether you mean that to apply only to each turn, or (incorrectly) to the whole game. After 2 turns the likelihood of still having a normal game is 25∕36×25∕36=625∕1296 (less than 1∕2) and it keeps going down from there. Having a full game of Séj where the dice do not once allow a deviation from ‘classical’ chess is vanishingly unlikely.

Are there any plans to restore this functionality? Not sure whether the ongoing procedures with backups ⁊c make this a more or less opportune time to look into this, so if the latter it can ofc wait, but it'd be good to have it back eventually

I've been thinking a little about these pieces, as well as the ‘helical’ crooked riders that Fergus suggested here.

It seems to me these are instances of (modulo one detail, which I'll get to below) the same pattern that brought us the ‘modern’ elephant — i.e. the FA — wrt the original 2‐space‐diagonal Elephant: we have an original piece with a non‐coprime (as Charles Gilman would have it) leaping move and fill in the gap.

As such, it seems to me that, in line with mỹ initial intuitions in both cases, it's probably clearest imo to think of the helical pieces and the 2.bent riders as variations on respectively and lama–osprey/zephyr–ostrich rather than totally distinct pieces (or for that matter as immediate bishop/rook/queen or manticore/griffin derivatives)

The main difference between these and the modern elephant is that, the original piece having riding tendencies already, it seems more natural to have the ‘modern’ component be lame/stepping rather than leaping as in the elephant case. The ‘running’ elephant (as coined in the previous comment) would be a lame/stepping FA, or equivalently a B2.

I wonder whether there are many other piece‐types for which ‘running’ (or indeed ‘modern’) subspecies are useful? Running dababba‐/alfil‐/alibabariders, skip‐riders (panda/bear/harlequin), and slip‐riders (Tamerlane picket ⁊ al.) are just rooks/bishops/queens (and ‘modern’ ones the same but less blockable and this probably OP); running crooked dababba‐/alfil‐/alibabariders likewise reduce to lame contrabrueghels/‐proselytes/‐halcyons. Running alpacas/quaggas/okapis/⁊c. (i.e. alternating pairs of orthogonal and diagonal steps) — straight, curved, or switchback — are perhaps more promising, and not, imo, all too exotic; running nightriders/roses/nightfliers/‐sidlers/‐ladies, the same but starting with a single step, also bear considering, even if not strictly non‐coprime to begin with.

There's one other curious difference between the bent and crooked members of this family: as described, the bent ones can only make the remaining part of its move if the non‐coprime part is made in its entirety (i.e. the ferz/wazir move is to the exclusion of the rook/bishop one), whereas the crooked pieces must make both componets regardless (this difference is more pronounced when considering the time‐reversed versions, i.e. running contrazephyr/contraproselyte/⁊c.: the former is committed to a full alfil leap if it starts with a non‐zero rook move — the alternative would be the existing fimbriated griffon — while the latter has to make its final turn and ferz step lest it become equivalent to the aforementioned running crooked alfilrider (as well as curtailing its first, rather than its last alfil run; the pair with one time‐inverted but not the other is also possible, if a bit obtuse)). I'm not yet sure how best to describe that difference without special‐casing.

tl;dr: new category of pieces (tenatively named ‘running’) combining recent suggestions, with some further suggested extrapolations and some unanswered questions re semantics.

Assuming anyone actually makes it through this, any thoughts?

I believe this page to now be ready for publication

I was scrolling through some old comments and have found what Aurelian would call a 3.manticore posited by Sam Trenholme in this comment, alongside the ‘3.griffin’ and a bunch of others (the ’2.manticore’ or ‘running osprey’ is in there as well). No names alas, but still interesting to see these pieces having been discussed 12 years ago (almost to the day!).

It seems to me (on the topic of that thread) that simply the fact of having to count to three rather than either changing direction immediately or simply foregoing any counting altogether (griffon/manticore and hook mover/capricorn respectively) makes the ‘3.manticore’ non‐simple from a player's perspective; the ’2.manticore’/‘running osprey’ is kind of liminal in that respect — two‐step moves are still easily visualised and trivially interpolated — though even it is in some ways arguably more complicated than the component of Tim Stiles' fox and wolf, which only has immediate turns.

When saying ‘four squares’, is that counted inclusively or exclusively? In the former case, both king and rook moving ‘four’ squares each would in fact land next to each other, on the bishops and adjutant's squares on the queenside and the marshall's and knight's on the commanderside.

Originally posted on Pemba, where this piece is called a Crocodile.

I assume JL means this one? His page includes it thrice: that ‘close‐up’ at the beginning of the Rules section, the full page featuring it after the list of volumes in Alfonso's book, and a reproduction on a commemorative stamp at the end of the page

The dragon is indeed a t[FR], in Betza's original notation. However, that part of it was never documented on the Betza Notation page (instead languishing on the Chess on a Really Big Board page, though it turns up elsewhere too), and is arguably a little underspecified, so H. G.'s XBetza (which is what the interactive diagram uses) specifies such multi‐leg moves in its own way. In this extension, FyafsF is indeed equivalent to the original t[FR]

The vulture afaict is mainly a longer‐range relative of George Duke's (and more recently Uli Schwekendiek's) Falcon, whose advantage over the bison (from a game design perspective) is its blockability — presumably the same is sought here. Unfortunately, due to the multiple paths to a given destination, it is quite complex to describe. Idk about the extra knight move though, that's perhaps a little gratuitous (presumably to make up for the basic vutlre's lack of maneuverability?)

I agree the birds are quite complex, if potentially interesting to play with? And whether the knight/elephant enhancements are truly necessary may be worth a playtest as well

Ok, having actually gone to find a copy online, I agree that Tressau specifies the Kb/j–Rc/i castle; in principle one could still object that the example games may not be played by the original rules (while he says they're real, rather than constructed, games, it could still be under the influence of a misunderstanding), but it seems upon a cursory reading that for the Sultan's Game in particular his book may in fact be the original source? The Emperors Game is cited in the Spielarchiv, but Tressau explicitly notes (p.80) that a game with a Marshal had been suggested there but not described, rather being rejected due to the necessary odd number of files being unwieldy (in particular due to either same‐colour bishops or transposition of one bishop but not the other with its adjacent knight).

Unfortunately a quick search for the Archiv der Spiele online appears entirely fruitless so I can't confirm that…

Apparently I forgot to add the link to the XBetza page in my previous comment; I've now added it there.

yafsF is indeed the sliding part. a is as you've found, ‘again’; fs for w's and F's is interpreted as for a king, so for an F it changes to a W direction — and ‘forward’ for anything but the first part of the move is interpreted as ‘outward’ (like Alfonso about the rhinoceros); y is a ‘range toggle’ i.e. it switches from being a leaper/stepper to being a slider. Thus, yafsF is one step diagonally followed by a 45° turn and sliding orthogonally.

Complexity is in the eye of the beholder. It's not immediately obvious (especially compared to t[FR]) but it's apperntly easier to describe to a computer (and easier to generalise), which for the interactive diagrams is a definite plus