Comments/Ratings for a Single Item

Note to CVP editor(s):

I've now finished submitting two presets tonight (that is, one for Hannibal Chess and one for Wide Chess).

Thank you.  They have been posted.

Tonight an idea occured to me for a chess variant, although it may need more work - for one thing there may turn out to be far too much chance in the game. I'm thinking along the following lines: the variant would use two standard 52 card decks, one for each player (or maybe just one deck, if Game Courier could handle that for use by both sides). After each card draw and completed turn by him, and then the same by his opponent, a player's drawn card is put back in the deck and it is re-shuffled, just prior to making his next one card draw. Each card in the deck corresponds to a square on the 52-square board, as depicted in the diagram of the setup that follows. On each turn a player first draws just one card, then may either teleport an uncaptured piece or pawn of his to that square, if it is unoccupied, with some restrictions, or else he may make a normal move according to FIDE chess rules (although the goal in this game is to actually capture the enemy king, so it's legal, though not productive, to not get out of check or walk into it). A player must either teleport or move normally each turn, and there is no stalemate in this variant.

The restrictions on teleporting not already mentioned would be that a king can never teleport, and a pawn cannot teleport to the first or last rank, nor can a pawn teleport to a rank behind the one occupied at the moment by the enemy king (else I thought many endgame races could become too much of a joke). Otherwise, it would be legal for a player to have 2 or more bishops on the same coloured squares after teleporting.

A 50 move draw rule would be in effect, except it applies only to there being no captures for 50 consecutive moves (pawn moves being now irrelevant to the rule). Three-fold repetition of a position is a draw, regardless of the card drawn at each move (a card drawn might allow a player by luck to avoid such a drawn game, e.g. by willingly blocking a checking piece with a teleported piece before the 3-fold repetition occurs). There's no draw by perpetual check due to the possibility of teleportation arising, so the 50 move rule (or 3-fold repetition of postion rule, if applicable) would be used instead to call it a draw, unless the players agreed to a draw. There's no castling, but double step pawn moves are possible from a player's 2nd or 4th rank (even if a pawn of his was teleported or moved normally to there in the past), and en passant capturing is possible in either case.

[edit:2 I'd tentatively estimate the piece values for this variant idea as: P=1; N=B=2; R=5; Q=R+B+P=8; K's fighting value=4.9 approx.].

If this idea for a variant still appeals to me after studying the following diagram at leisure, I'm thinking I may call it 52Chess [edit: this variant idea may well be infeasible, as the centre might often become rather clogged by pawns, and then perhaps only great luck might allow a breakthrough, if soon enough in the game, either that or risk trying to exchange a minor piece for two pawns if ever allowed, which actually might often be an equitable trade [edit3: this seems so, if my value estimates are right, and rest of the previous sentence seems a bit doubtful in hindsight]. Also, too many pawns might often be traded off in a game, and games might hardly ever be won with a nice quick attack. [edit3: this last point not so terrible, as there's lots of slow paced variants]]:

 

I'm posting an idea I have for a 10x8 variant idea, for my study at leisure. The extra piece beyond the FIDE ones in the setup is the Champion piece type from Omega Chess, WAD in Betza notation (Wazir, Alfil and Dabbaba compound piece). I'm thinking of calling this variant idea 'WAD Chess', if I eventually submit it. I wanted to have every pawn in the setup protected, and wound up unawares with a segment of each of Fergus' Gross Chess armies' setups, but on 10x8, for the composition & deployment of each side's army in WAD Chess. Long ago I tried this setup with Waffles (rather than Champions), but found that the problem for players of developing those pieces from that setup (or others I conceived of) would seem to have been irksome. For a 10x8 board I tentatively put P=1; N=3.38; B=3.75; Ch=4.29; R=5.5; Q=10.25 and K's fighting value=3.2; also note that a WAD piece comes close to the average value for all non-pawn pieces in a chess army, IMHO, possibly in itself making WAD Chess a bit more of an interesting extension of chess. Note that it seems a lone WAD and K can always force mate against a lone K on a 10x10 board. Otherwise, rules would be similar to those for Capablanca Chess, e.g. in regard to castling [edit2: using Wide Chess-style castling rules seems to make this idea more palatable, as it would also for a similar 10x8 Waffle/Pheonix Chess idea setup, too).]:

[edit: Backup setup, using chess' castling rules - may be worse than original setup, e.g. if move c- or h-pawn and wish to deploy bishop to 3rd rank, possibly to trade it, or if develop both WAD and knight on one side of the board, rook's pawn there may be unguarded on its original square more often, plus castling rules may leave kings less safe less often, even on kingside, not to mention WADs initially farther from centre - an upside of backup setup is that WADs & Ns/Bs possible initial developing moves never overlap {edit: possible problem: enemy charging b- or i-pawn may make it hard to develop WAD on adjacent file!}:]

[edit: 2nd backup - drawback is it's at the least rather ugly:]

[edit: Below are 2 possible alternate 10x10 setups for the WAD Chess variant idea; pawn rules would now be as in Omega Chess:]

Backup setup idea (it's as for Omega Chess, minus the wizards and off-board corner cell - already a possible drawback):

WAD (Champion):

Tonight I've thought of a 12x8 variant idea, the setup diagram of which I'll post here for my study at leisure. Aside from the usual 6 chess piece types, there are the champion (from Omega Chess, called WAD in Betza notation) and nightrider types I've added in, in a way that leaves all pawns guarded in the setup. If I submit this idea eventually, which I may dub 'Wide Nightrider Chess', I'm thinking of using the same quirky fast castling rules that I introduced in my earlier 12x8 variant (Wide Chess). That is, the castling rules for Wide Nightrider Chess are as follows: A king that has never moved, and is not in check, can 'leap' once a game, along the first rank, to any unattacked empty square between it and an unmoved rook, followed by said rook 'leaping' to the king's initial square so as to complete castling in one single move. It does not matter if any squares in between are occupied or under attack:

A possible downside of the setup is that after such a 'traditional' opening as 1.g2-g4 g7-g5, White has 2.Bh1-e4 and he is threatening to take on h7 thanks to his kingside nightrider, although Black appears to be 'okay' after defending against this with his kingside champion or knight (e.g. 2...chj8-h6 and if 3.f2-f4 chh6-g6 seems okay, so that if 4.Be4xg6 f7xg6 5.f4xg5 qf8xf1+ 6.Kxf1 then 6...nnk8xh2+). Note, however, if in the setup all the knights were switched with the nightriders on their own wing, the move 1.g2-g4 would just lose the g-pawn to Black's kingside nightrider, given that possible alternate setup.

My tentative estimates for the piece values in Wide Nightrider Chess, on its 12x8 board size, are: P=1; N=3.06(or 3 approx.); B=3.75; CH=3.86(or 3.75 approx.); R=5.5; NN=N+(N-1)x3/4+P(on this fairly large board size)=5.6(or 5.5 approx.); Q=B+R+P=10.25 and a K's fighting value=2.67. [edit: Note a lone CH and K can always force mate against a lone K on a 12x8 board (in 37 moves at most - H.G.).]

[edit: Below is my backup setup, which I'm currently preferring (plus see my next post in this thread); since composing this second setup, I've noticed that on smaller sized boards (8x8, 10x8) in the Nightrider Armies presets, nightrider pieces are frequently consigned to the boards' corner squares or the squares next to them. I'd use my fast castling rules with this backup setup too, since e.g. castling long always in Capablanca Chess castling rules style might very often leave a number of queenside pawns vulnerable:]

[edit: Below are 2 possible setups for 12x10 version variant idea, not named as yet. Pawns would move as in Omega Chess:]

Backup possible 12x10 setup (doesn't seem as good due to nightriders'/rooks' locations' possible early effects on opening phase of a game):

I just realized that the original setup for my Wide Nightrider Chess idea (in my previous, now edited, post) seems flawed due to e.g. 1.d2-d3 (or 1.i2-i3) 'threatening a nightrider fork' (on White's second or fourth rank) of a Black rook/champion and central piece. This might compel Black to soon rather unproductively move his b- (or k-) pawn forward one square to block the enemy nightrider's path to his rook, or else to develop his nightrider on the other wing to the edge of the board in reply. That's unless Black is prepared to allow the trade of a (champion-guarded) rook for a White nightrider, which I'm not sure is a totally bad idea, especially in the opening phase (and nightriders may be in general fully worth rooks on 12x8, somehow, too). There is also the possibility of a [irritating?!] nightrider fork threat if one of that pieces is first developed to the 3rd rank, towards the centre. A solution that I'm currently preferring might be to use my somewhat less aesthetic(?) backup setup (using the same fast castling rules still), with the nightriders in the corners (i.e. I've in that setup switched all of them for all the rooks, and all the knights for all the champions, on all their respective wings). However, note then that kings might sometimes prove less safe after castling, at least on the kingside compared to chess, and perhaps the nightriders may not often be easily developed without possibly having to move again soon (also, if one goes to the third rank at move one, there is still the [now perhaps far less irritating] possibility of a 'nightrider fork' to think about). My earlier WAD Chess idea in this thread may be slightly problematical, too, as developing all the pieces might still too often prove to be somewhat awkward to arrange, in spite of my upgrading from Waffle to WAD pieces for the [preferred original] setup. Thoughts on either of these variant ideas, anyone?

P.S.: I noticed on the internet (not in the CVP main index) that the name Nightrider Chess has already been used, though perhaps always with a Roman numeral after it to indicate which particular variant of that series of games it is. Also, unrelated, I did some slight editing of my last, long, comment re: the Centennial Chess page.

Note that on 8x8 the Nightrider is usually a bit stronger than the Rook (5.25-5.5 vs 5). And I don't expect that to be much different on 10x8. On the contrary, I expect a Nightrider to benefit more from a larger board dimension than the Rook, because its far-away moves are relatively close by (and thus less likely to be bocked).

I've seen the odd opinion that it's tough to design a good variant with the high mobility nightriders for play on smaller boards such as 8x8 (Fergus seemed to manage to do well with his 8x8 Cavalier Chess, though).

It's good to see H.G.'s view that nightriders compare well with rooks on 10x8, or on even larger boards, such as for the 12x8 Wide Nightrider Chess idea I'm looking at still. It might not have the frequent ease of piece development in actual games I'm wishing for, but if nothing else the fast castling rules for it may help its cause somewhat, perhaps in comparison to some/many already existing games that use such boards. It'd be nice if software supports variants with such novel castling rules, but I fear they don't, at least without some considerable work.

It'd be nice if software supports variants with such novel castling rules, but I fear they don't, at least without some considerable work.

Indeed, this is the reason I added Hanibal Chess to the newest version of ChessV but not Wide Chess.  That said, it wouldn't be all that difficult to add support for a "fast castling" rule in the same way it already has support for "flexible castling", although other engines aren't likely to implement it.  The current (unfortunate) situation is that we currently have a bunch of 10x8 engines that can play some Capablanca variants, but almost none support flexible castling, so they can't play Schoolbook, Grotesque, etc.  So, when desigining a variant, this is something to keep in mind.

Another consideration - if we were to create a universal "fast castling" rule, does it require the king to move at least two squares?  If so, this eases implementation, at least somewhat, because a move can be cleanly defined with only from square -> to square (and optional piece in case of pawn promotion.)  Flexible castling requires the king to move two squares for this reason.  Otherwise, a king moving a single step can be ambiguous.  For purposes of support in ChessV, this isn't a big concern, as the architecture will automatically throw a dialog box at you when a move is ambiguous.  See Wildebeest Chess as an example, where a king can castle while moving only a single square, although this game is unique in this regard as far as I know and it would have made life easier for all involved if R. Wayne Schmittberger had taken this into account, especially since you probably aren't going to want to move your king a single space when castling anyway.  In any event, that bridge has already been crossed ...  Although, even outside of computer play, you'd probably want to give some thought as to how moves should be annotated in general.

Hi Greg

In case of my Wide Chess variant's fast castling rules, it's perfectly possible for a king to move just one square, I'd hope was clear from the wording of that game's rules. I don't feel too bad that this is so, since a king moving just one square in castling (or even moving zero squares) is possible in Fischer Random Chess thanks to some possible setups. On the other hand, in the case of my Wide Chess, the fast castling rule I came up with is complicated by allowing the king to pass over attacked or occupied squares during the castling process. I've since seen another variant where attacked squares can be passed over, but not occupied ones, and I cannot recall other details of that variant's castling rules, not even the variant's name unfortunately.

Castling where the King moves a single step, with the resulting danger of ambiguity, can also happen in Chess960. This is not a problem for notation there, as there is only one type of castling, so O-O or O-O-O suffices. But it is a problem for computer interfaces. The conventional solution is to enter castling by dragging the King onto your own Rook. (Or click Rook after selecting King, in the case of click-click moves.) In WinBoard I elaborated on that idea for Seirawan Chess, where castling can be accompanied by gating, either at the King or at the Rook square. To indicate the latter, you can drag your Rook onto the King. It does need a disambiguator in notation, however. (O-O/Eh van O-O/Ee.)

With flexible castling this method could be used to indicate castling where the King moves a single step (sO1 in XBetza notation). All other castlings can be entered by moving the King; there is no ambiguity for those. (At least with an orthodox King.) This allows all castlings to be entered by dragging a single piece, or separate clicks on from- and to-square.

When pieces that can move more than one step by itself, it is a bigger problem to allow indicate their castling. The 'advanced' variant of Omega Chess poses this problem: there the Queen can castle with a Rook ('Guarding'). To handle that I generalized the 'friendly-capture' method to multi-leg moves, using locust capture of a friendly piece as a signal that you want to castle with it. WinBoard supported such two-leg locust captures (where the final destination square is not implied by the victim, or vice versa) anyway, to handle the Chu-Shogi Lion.

I'm a bit more encouraged about the feasibility of my 10x8 variant idea WAD Chess now (see earlier in this thread), and also encouraged a bit about the possible feasibilty of my (12x8) variant idea Wide Nightrider Chess . That's since I've checked various (10x8) Capablanca Chess-like variants' setups just to see how awkward (rather than normally smooth) piece development might appear to often be for a given game of each. I was rather amazed that Victorian Chess has been played so much on Game Courier, though perhaps it being a variant with a historic sounding name might explain that to some extent. Grotesque Chess and Ladorean Chess also arguably have awkward setups for piece devopment for in an average game; the former has been played 7 times so far on GC, while the latter has yet to be played. However I've never played these games, so I cannot be too sure how awkward development might often prove for a player in any of them.

[edit: It looks like either possible setup I've got for WAD Chess or for Wide Nightrider Chess is too flawed [edit2: Wide Chess-style casling rules may make 10x8 WAD Chess work better, as I noted with an edit2 to an earlier post]; e.g. in the backup (till now preferred) setup of the latter, edge pawns being vulnerable can cause problems in the event of castling if desired, especially on the kingside.]

In reference to a post I made about fast castling in Wide Chess two posts back in this thread, I think I may have found the variant invented by someone else that I now see had slightly similar (but far from identical) quirky castling rules, in that having the king move over attacked squares is allowed:

21st Century Chess

Below is a possible variant idea setup I'm now looking at, in quest of a (IMHO) better (i.e. viable) setup for my Wide Nightrider Chess variant idea. Castling rules would still be as in Wide Chess, while pawn rules would now be as in Omega Chess, for this 12x10 board (has the drawback, if it is one, that WAD+K cannot always force mate vs. lone K on a 12x10 board [edit: H.G. wrote that mate can still be forced here, in a later post in this thread]):

I'd tentatively estimate the piece values for this 12x10 variant idea as P=1; N=2.83(or 2.75 approx.); WAD=3.48(or 3.5 approx.); B=3.75; R=5.5; NN=Nx2(on this very large board size)=5.66(or 5.75 approx.); Q=R+B+P=10.25; K's fighting value=2.1 approx.

Below is a possible variant idea setup I'm now looking at, in quest of a (IMHO) better setup for my WAD Chess variant idea. Castling rules would still be as in Capablanca Chess, while pawns rules would now be as in Omega Chess (which has a slightly different setup, that is for the 10x10 portion of its setup), for this 10x10 board (note that Dr. Muller has informed us that on a 10x10 board, WAD+K can always force mate vs. lone K). I thought about using nightriders instead of WADs in this 10x10 setup (or another), with pawns being on the 2nd rank of each side, but the idea seemed less viable, moreso perhaps with orthodox Capablanca Chess castling rules being used [edit: this 10x10 WAD Chess variant idea seems inadequate to me too; the WADs seem awkward to place no matter what the setup, with them and the FIDE armies, and in any case it may well be reminiscent of Capa's rejected 10x10 version of his Capablanca Chess in that games may be long on average, not to mention it may be seen as a pale version of Omega Chess] :

I'd tentatively estimate the piece values for this 10x10 variant idea as P=1; N=3; B=3.5; WAD=3.78(or 3.75 approx.); R=5.5; Q=R+B+P=10; K's fighting value=2.5 approx.

A slight disappointment I currently have with both these setups is that now neither variant idea would have a 50% pieces to empty cells ratio in the setup, but this may be a small price to pay if these setups are otherwise viable.

[edit: diagram for 12x10 Wide Nightrider Chess with FNs instead of Ns (I'd estimate here a FN=4.4{or 4.5 approx.}) - I think I may definitely prefer this idea after all, as a WAD is slightly closer to a FN in near-exact value than a N is to a B, on 12x10, and for this size board IMHO a B is worth at least a NF before the endgame phase:]

[edit: Backup setup (don't really like this too much as Bs hit edge Ps in setup; switching Bs and FNs - for a second backup setup - also not liked, due to a Bs conflicting with opponent's same coloured B if one diagonal or the other is opened for a B - and it's a similar story for certain backup setup(s) for 10x10 WAD Chess idea [see further below]):

Diagram for 10x10 WAD Chess with FNs instead of Ns (I'd estimate here a FN=4.78[or 4.75 approx.]) - I think I may definitely not prefer this idea, as a N is considerably closer in value to a WAD than a B is to a FN, on 10x10:

Champion:

Nightrider:

Ferz-Knight:

[edit: alfaerie-many diagram for 12x10 Wide Nightrider Chess (with FN's):]

alfaerie-many Champion:

alfaerie-many Nightrider:

alfaerie-many Ferz-Knight:

@Kevin

Hi,

I like your 12x10 idea with nightriders and champions. If you do a preset, I'll try it with you. Make two personalized challanges against myself, maybe we'll play with reversed colors.

@Kevin

I was thinking. Would you consider replacing knights with ferz knights as they are here the weakest pieces. Ferz knights will still be slow, but I think quite apropiate for local duties. This would make the ferz-knight close in value to the champion, so more interesting exchanges. Also between them the ferz knight and the champion would cover all 24 squares 2 squares away from the piece, making them simetric. On the other hand the bishop would lose in relative value :(!

If you're going to augment the knight, I think the wazir move is a better choice because it maintains the property that the knight changes colors with each move and thus cannot triangulate on a target.

Thanks for the suggestions and/or support so far guys. I'm a little tired tonight so I'll be taking even more time thinking these variant ideas over as a result.

I assume the suggestions are for the 12x10 version of Wide Nightrider Chess. I had my heart set on being a purist as far as keeping the 6 FIDE piece types intact, plus adding in two rather orthodox fairy chess types, and the champion and nightrider types appealed to me the most, partly because they move symmetrically and partly because they are close in value to minor piece or rook values repectively, even on this size board. I also have a bit of a problem with adding a ferz or wazir (even if move-only) component to a knight, because in my own ways of estimating their values, such a compound piece would be worth more than 4 pawns even on this size board. If H.G. were to differ on that estimate, I could at least quote his view however. In any case, another idea is to have a mutator variant(s) on Game Courier where either of these compounds is used instead of knights. As an aside, I find 12x10 more of a possible acceptable size for a physical board, if ever made, as 12x12 would be rather long for a coffeetable without possibly reducing the scale of the pieces and squares even more significantly than, e.g. 10x10. Coffeetables and tournament hall tables are normally rectangular, you see.

Some comments on my 10x10 version of WAD Chess: I like that WAD+K can mate lone K unlike for Omega Chess's strange board, which physically needs smaller scale squares (if not pieces) due to the extended length and width of the board compared to a nice clean 10x10 board, so in that sense too I hope less is more. I moved to 10x10 for WAD chess since the 10x8 version had the bishops hitting the edge pawns in that setup, and perhaps often leading to fast bishop trades. It's not clear to me that on 10x10 (or even 10x8) that a B is really worth less than a WAD though, at least before the endgame. I saw on a write-up for Omega Chess's piece values (on it's commercial site!?) doubt about even trading a B for a WAD being okay before the endgame, I think. I didn't like the idea of using a setup similar to Omega Chess for 10x10 WAD Chess (though I added a diagram for it in an edit to a much earlier post, as a backup setup). Even with the wizards and their extra corner squares added, I don't like Omega chess' castling rules leaving the king far from an edge pawn with this game's setup - but also normally I kind of like rooks being in the corners to help that, and for tradition's sake, too.

My preferred 10x10 WAD Chess setup has the disadvantage (besides the slight clash, perhaps, for ideal squares to develop minor pieces to on the 3rd rank) that if a knight is developed towards the centre, and the WAD on the same side leaps forward, they might be threatened with a pawn fork, though that takes longer to happen than on 10x8. There is also that castling would take longer than in Omega Chess' setup. However there's one more thing I don't like about that game's setup, and that's that edge pawns (if unmoved) may be vulnerable to a hit at least, before or after castling, unless their close WAD piece stays close, sadly on the rim or corner that is.

Lots of pros and cons for me to weigh here about the setups, and about suggestions thus far. :)

@Greg

I'm not sure that is a better idea. They are mostly the same, and color switching is not such an important property. But the wazir move already goes to the champion. There are just to many wazirs. Anyway it is Kevin's decision after all :)!

@Kevin the point was to make the knight more competitive as it loses strengt on larger boards. On a 12x10 it does not feel much like  a knight anyway :(!

Thanks for the advice Aurelian (and Greg). I'm still weighing it.. I know that Fergus used knights, still, on the even bigger 12x12 Gross Chess' board (though that game had lots of other pieces), and many times they have been used on 10x10. There are very few 12x10 variants in the database, so hard to compare the design to any such others! By my own way of weighing things, a knight is as about as close to being a competitive minor piece on 12x10 in one way (being a bit weaker than the other minors on average, perhaps) as some sort of an augmented knight (as suggested) would be in another way (being a bit stronger than the other minors on average).

If I accept the idea of using an augmented knight instead of a knight on 12x10 (attractive in one way since a nightrider already has a pure knight move, and then some) there are pros and cons to augmenting it either way suggested, i.e. either with a ferz or a wazir component, and it's not clear which way makes more sense, so perhaps it's a matter of taste. There is the 'theme' of using a ferz component to compliment the WADs wazir component, but it's also a theme just to use a knight,, to keep the 'pure FIDE pieces all used' idea; Greg's point of a (ferz-) augmented knight being capable of triangulating should not be taken too lightly either, as the whole idea of augmenting is to arguably improve the piece, rather than keep it pretty by sticking to some sort of artistic theme. A lot to agonize about here, in deciding on the final design. :) I hope no matter what I decide, I'll give that design a fair chance of becoming 'popular', perhaps even much later, even outside of the internet.

[edit: I've thought of a somewhat contorted way (given this is fairy chess, after all) to try to better justify (at least in my own mind) adopting Aurelian's suggestion of a ferz-knight compound in place of each knight in the setup, perhaps a justification that might make everyone happy (famous last words...). That is, a nightrider is a knight-like piece that cannot triangulate [edit: actually, it can!], while a ferz-knight piece is a knight-like piece that can, so they kind of complement each other. Thus, using instead (or adding also, if that were possible) a wazir-knight piece might not be seen as so desirable, for an additional artistic, if not also practical, reason than Aurelian wrote to Greg about. There's also the question in my mind as to why a ferz-knight piece should ever be used at all, if triangulating ability is always a practical drawback for a knight-like piece being used in any variant, and I'd hazard to guess that at least for some variants and their setups, a ferz-knight piece does have the right to exist. So, now I'll really have to study Aurelian's setup change idea even more. Note that in each of the two 12x10 variants in the database that I can find content for, knights (plus all the rest of the FIDE armies) are used, however, and one of these uses just 24 units per side in the setup.]

I've added an edit to my previous comment.

Since then, I looked up an old piece type article on CVP (values of many pieces/pawns as found by ZoG, back in 2001) and found that a FN compound was thought to be almost worth a rook on an 8x8 board (while WN was rated just a shade more than a rook), and I would note that in this old article I've noticed many instances where I thought the value given was an underestimation more than the opposite (note that the value of a chess pawn is given as 1888.135, to better understand the scale used):

http://www.chessvariants.com/piececlopedia.dir/whos-who-on-8x8.html

I would definitely expect an NF to be worth more than an NW, although the difference would be microscopic.  Not only can the NF triangulate, but a Ferz is worth more than a Wazir.

Agreed, pretty much. I usually equate ferz' and wazirs values for the purposes of having easier formulae for myself, but it seems likely that ferz' are worth just a little more, if anything.