# Mahjong board formation and drawing rules

In Mahjong basic rule (this one for example), the board is setup in a spiral formation and the tiles are drawn in order from the 4 draw piles. With all the tiles facing down and shuffled, the probability of drawing a specific tile from any pile in any order is the same (unless I am missing something?). If this is correct, the game can technically be played with one draw pile and tiles can be drawn from anywhere in the pile?

There are also additional draw rules such as a “special deck” (near the end of this video), which is completely superficial?

I came up with this question when my date and I decided to play Mahjong in the park on a picnic blanket, setting up the game was rather difficult on this uneven surface.

• Yes , it's correct. The rule is there only to help enforce randomness, as tiles are more difficult to shuffle / mix well. Mar 6, 2021 at 15:10
• How would the rules help to enforce randomness? Mar 6, 2021 at 22:56

In theory yes, you can play with a single pile. The reason people setup the wall this way (aside from historical reasons) is because the layout suits the nature of the game. You typically play on a square table and tiles are fairly large so stacking them in a single tower would be pretty dangerous. Also, after setting up the wall, players draw their hands from the wall which is done in sets of 4 tiles at a time going around the table. The layout makes it easy to draw the tiles, while also encouraging the social aspect of the game.

• Oh, I didn’t mean a 1x1 tower, more like a pyramid Mar 7, 2021 at 2:50
• Ah, I guess that makes more sense. Some things still apply like the way tiles are drawn. Also with the pyramid, you'd lose the "draw from the back" rules for kong/flowers Mar 13, 2021 at 6:13
• “Draw from the back” is superficial, drawing from anywhere gives you the same result Mar 14, 2021 at 10:23

I used to be a member, and for a time the President, of the MSU Mah Jong club. The custom used there built the wall as a square that overlapped at the ends, not as a spiral as shown in the linked video.

From a game mechanics point of view, building the wall is comparable to shuffling cards and leaving a scuffled deck to draw from. in terms of randomizing the draw, building a pyramid, or just mixing a pile and drawing at random, as is done is Scrabble, would work as well. But the shape of the wall gives an instant alert if a tile has been dropped or is in some way missing from the table. That is the wall will not come out even if a tile is missing. The square shape also suits the square shape of a table, as the answer by Matthew Ban Kim suggests. Also, "compensation" tiles for flowers, seasons, and displayed Kongs is taken from the back end of the wall, which could not easily be done without something like the wall. This affects the maximum possible length of the game. Besides, th wall arrangement is traditional, and I see no advantage to using a pyramid shape instead.

• I’m not familiar with the compensation tiles that you mention, how would they affect the maximum possible length of the game? Regardless of the setup, the number of tiles are equal and hence, same game length, correct? Mar 7, 2021 at 21:35
• For the missing tile problem, if the single pile is rectangular shaped (e.g. 6x6x4), one can also immediately know if a tile is missing Mar 7, 2021 at 21:40
• There are variants that use an non-trasparent bag instead of a wall, like Washizu mahjong. Mar 8, 2021 at 7:07
• @Fried Rice As I learned to play, a break is made near the end of the wall, leaving the last 16 tiles in a separate group. If the draw gets to the break, the game is over. When a playuer draws and faces a flower or season, an extra tile is drawn from the back end (back pile) to keep the active hand at the same size. Similarly, when a player faces a kong (4 of a kind) an extra time is drawn from the back pile, so the same number of combinations can be formed. Such "compensation" draws bring extra tiles into play, and slightly lengthen the maximum possible no of turns in play. Mar 8, 2021 at 20:52
• So with this rule, having a main pile and a side/back pile would also work? Mar 9, 2021 at 0:53