ASSUMING KING IS ON D-FILE AND FERZ IS ON E-FILE
!!!THIS BLOG IS AN AMATEUR ASSESSMENT FOR PURPOSE OF INDEPENDENT RESEARCH+OBSERVATION AND IS TO BE REVISED AND EDITED, SOME INFORMATION MAY BE INACCURATE SO ADVICE/CORRECTIONS ARE WHOLEHEARTEDLY ACCEPTED!!!
1: Piece movement, function and value
These are rough personal estimates based on discussions I've seen and games I've looked at+played. I believe the value of pieces in shatranj are more subjective based on circumstance, game phase, and positional play. It's played a lot like a buffed rooks and knights middle/endgame, in the sense that pieces can often be sacrificed for optimal pawn play, and that forward momentum is often top priority, rather than attacking the opponent's king or actively hunting them down (at least until later in the game, or when there's a decisive advantage).
-Rook (rukh/chariot): 6 points. Moves side-side and up-down, but cannot pass through pieces, like a modern rook. Most valuable and powerful piece; having connected rooks, doubled rooks on an open file, or using them to support a pawn storm all become more significant threats.
-Knight: 4 points. Functions like a normal knight, but with more proportional value+power in shatranj. Knight outposts are powerful because of this.
-Ferz/firzan ("queen"): 1.5 points. Moves diagonally forwards and backwards: colour of your ferz may determine how pawns advance, as well as position of alfils.
-Alfil ("bishop"): 1.2 points. Alfil's have limited squares (8 squares each to be exact) which makes them negligible attacking pieces. They are more useful for supporting pawn advances and restricting higher value pieces; for example, the c5 square for white is the same colour as the diagonals of the kings alfil and the ferz, so the kings alfil will often be placed on a3 to support c5. In some positions, alfil's can be sacrificed to damage the opponents position and/or to improve your own, e.g. creating a difficult to defend passed pawn on an open file.
-Pawn: 1-1.5 points. Pawns only move one square, and due to the restricted movement of certain pieces like the alfil and ferz, pawn value becomes relative. C, D, E and F are regarded as most valuable, because they are typically used to build a strong center supported by flank pawns, minor pieces and knights, and sometimes rooks (with C and F being useful for prying open the center and creating outposts in some cases); A and H can be valuable for supporting flank storms and taking space, while B and G are valuable for restricting enemy piece movement (specifically alfils) and supporting both flank and center pawn pushes.
2: OPENING
Shatranj openings work differently than modern chess openings: because of slow pawn movement and more restricted movement of the "bishops" and "queen", it puts more emphasis on building up a strong pre-"first blood" formation rather than a dynamic and immediate exchange of blows. There isn't the piece range and quick development required to gain an immediate opening advantage, or play for immediate tactics. These "pre-first blood" formations are called ta'bi'at; they are less nuanced than modern chess openings and are more open to modification, and at higher levels people sometimes develop their "own" ta'bi'at based on their playstyle. Most ta'bi'at can be played without concern for the opposing players moves opening (at least at beginner levels), although some may be better suited or worse suited against others. All this taken into account, castling/getting your king into a bunker isn't as important as supporting a strong pawn structure, controlling space and restricting your opponents piece mobility. Because of this, it's often ideal (but not always, depending on the situation) to keep most of your pieces behind your pawns, in order to both support structure+potential pawn storms/breaks and keep your pieces from being attacked+pushed back by the enemy's pawns or lower value pieces. Because shatranj is very positional, it is difficult to come back from overextensions in the opening if the opponent punishes them, because the pieces are generally too slow and not adequately coordinated for a counterattack. Unless you're playing by a ta'bi'at, you have to make sure every move you make has a purpose either immediately, for the future, or both. even if it's as small as taking a little extra space, any purpose is a good purpose as long as it's a clear purpose, and your opponent doesn't have any advantageous moves to reply with. It is usually ideal to obtain control of squares from a distance (via building pressure and building up adjacent pawns) before actually pushing pawns to those squares for this reason, though circumstances may vary. It is important to make sure the opponent can't place an uncontestable pawn onto your side of the board, especially the C pawns and F pawns (due to potential support from alfils on c5, c4, f5 and f4), and being potentially supported by both flank AND center pawns, which makes them versatile).
In this game between shatranj researcher @samuelebeckis and top shatranj player @coolthing , it starts out fairly normal with 4 center pawn moves by each player. As the opening progresses, white develops their own signature ta'bi'at: it is reminiscent of an as-Sayyal style pawn structure with early Masha'ikhi style alfil development, but with white sacrificing an alfil on b5, hoping for a space advantage and to damage blacks slightly more passive mirror-style shah-side structure (especially after his first knight move, the alfil attack becomes much more powerful because it also hits the knight and forces it to retreat). Black accepted white's alfil "sacrifice" on b5 (a mistake), which allowed white to open black's position via the C file (thus eliminating c4 possibilities for black) and place a well defended pawn on b5 (hence the as-Sayyal theme of this particular ta'bi'at), restricting blacks kingside movement and pushing his light squared alfil back. This allowed white to stockpile pressure onto c5 with the knight, alfil and rook. Black cannot adequately defend the shah-side (even though trying for a knight reroute and ferz sacrifice in exchange for the b5 pawn may be beneficial, as it could create double isolated pawns for white and also weakens the c5 pawn break, although it allows white to get a vast lead in development. Plus white's ease of development in supporting the C-file makes it a constant future threat, and puts black at a constant disadvantage) and opts for ferz-side counterplay, but it is already too late, as c5 is eventually successfully played and blacks ill-equipped shah-side position falls apart. This is an example of a SUCCESSFUL pawn push that shows the importance of solid pawn structure as well as prioritizing comfortable (rather than risky or unnecessarily passive) development, because despite losing an alfil white gets a b5 pawn that restricts black's movement and is very hard to contest, thus making a pawn break in the future extremely hard to defend against due to the more passive nature of blacks pieces, which we see as the game progresses: https://www.chess.com/variants/chaturanga/game/38644314/0/1
On the other hand, here's an example of when a pawn is UNSUCCESSFULLY played to the opponents side of the board (early push with inadequate defense) and proves to be an overextension. (Also an example of why putting pieces in front of pawns is dangerous). Black puts 2 pawns in the center and develops his pieces likewise, which resembles modern chess but is an unusual and debatably inaccurate playstyle for shatranj because it restricts pawn mobility and therefore structural integrity (this is because in shatranj, especially in the opening stage, center pawns are generally supposed to be defended by other pawns, due to the restricted nature of piece development, so if they aren't adequately defended they can become appetizing targets). Although it does resemble an "All Out Attack" (a more edgy ta'bi'at where pieces are developed to the center, and is similar to the "Armpit Attack" which is basically the crab opening of shatranj that and is considered a junk opening by high level players) except with D and E pawns being pushed instead of A and H pawns, which could potentially be even weaker than the "All Out Attack" since the edge pawns are supported by both rooks and knights. Taking space with flank pawns can prove to be good when your pieces are in the middle, because it can do more to prevent them from being kicked out by restricting enemy pawn play, and can also possibly lure the enemy into overextending their center and being punished for it, which is a very edgy approach to shatranj). I counter his center-based approach by making flank moves that restrict his alfils and knights, meaning they will likely need to reroute anyway. He commits his e-pawn to e4 early, allowing me to take space on the ferz-side and pressure his e-pawn with my knight. I push my d-pawn , because if taken then my light-squared alfil takes back and further supports potential ferz-side pawn advancement by monitoring f5. The cluttered nature of his pieces meant he had to reroute some of them into better positions, which allowed me to reroute my kings knight to target e4 and initiate a trade in the center. I win a pawn and eliminate both of his center pawns, weakening his position and allowing me to comfortably develop and dismantle his kingside (or shah-side as it's commonly called). He initiates some counterplay with his rook on my ferz-side due to me getting tunnel vision on his kingside, but i still have enough time to guard everything. However he blunders his ferz to a fork and ends up resigning
https://www.chess.com/variants/custom/game/60669064/74/1
Firstly, just putting this out there in case anybody has good resources for learning about shatranj+chaturanga, and the different kinds there are. I believe I'm currently studying the Iranian version, which I played in this game: https://www.chess.com/variants/custom/game/60669064/74/1
I am also interested in joining groups+discussions about shatranj theory, ideas and principles.