Some notes on 4-wide (Warning: fumen-stravaganza)

[caffeine]

Recently I've finally got around to learning how to do a 4-wide combo. I figured since I was thinking about these ideas anyway, I may as well leave them here for other players, who are also new to the 4-wide, to read. The first thing I want to point out is this guide, and more specifically, this picture.*

So, what I've been trying to do is simplify this as much as possible... to come up with "rules of thumb" to follow. The first thing you may notice about the site I mentioned in the above paragraph is that for any case, the I-tetromino has a maximum of two solutions and always at least one (the horizontal orientation). The O has 0-1 solutions per case. The zigzags (Z and S) and T have 0-2 solutions per case, and the guns (L and J) have 0-3 possible solutions per case.

I find it useful to be familiar with the cases that may look like a continuation at first, but they will actually lead to a dead end. It's good to sort of logically deduce what options you have left by looking ahead at what sequences will lead to deadends and crossing them out, so to speak. Then, you have a smaller list of candidates for sequences of placements that may actually continue the combo.

You have to remember that the hold feature effectively gives you two active pieces at any one point. Say you have an active piece J and your held piece is a Z. Well then, technically you can use either of them right now. At any point in the game, you have two pieces at your disposal (unless you've used hold already on the current piece or the active piece and hold piece are the same). So then, if one of those two pieces will lead to a deadend, then you know right away that you'll need to use the other piece. If you have more than one option for said piece, and one option leads to a dead end and the other doesn't, then you've just figured out how you need to place that piece (the only option that won't lead to a dead end). Often, we'll only have one option, and it's easy to decide where to go. However, it is very important to recognize cases where both your hold and active pieces will work or when you have multiple options with one or both pieces that will work. These are the times you need to look ahead in the queue and figure out which ones will lead to deadends further down the road.

Dead ends
Try to avoid the following cases (unless you plan on ending the combo soon anyway).
[fumen]110@lcC3jbF3jbF3jbF3jbG3gbE3HcC3jbF3hb8egbF3hb?8egbF3hb8egbH38eD3pbJHj[/fumen][fumen]110@lcC3jbF3jbF3jbF3hbH3hbA3gbC3HcC3jbF3jbF3gb?RpgbH3RpF3gbA3hbC3pbHHj[/fumen][fumen]110@lcC3jbF3jbF3jbF3jbG3gbE3HcC3jbF3jbF3gbkzhb?F3gblzgbH3kzD3pbMMj[/fumen][fumen]110@lcC3jbF3jbF3gbsshbF3usG3hbE3HcC3jbF3jbF3jb?G3ibH3hbC3pb15j[/fumen][fumen]110@lcC3jbF3jbF3gbsshbF3tsH3gbssgbD3HcC3jbF3jb?F3jbH3hbG3ibC3pbt5j[/fumen][fumen]110@lcC3jbF3jbF3gbsshbF3tsH3gbssA3gbC3HcC3jbF3?jbF3jbH3hbF3gbA3hbC3pbt5j[/fumen][fumen]110@lcC3jbF3jbF3hbssgbF3gbtsgbH3ssD3HcC3jbF3jb?F3jbF3jbG3gbE3pbN5j[/fumen][fumen]110@lcC3jbF3jbF3hbssgbG3usG3gbA3gbC3HcC3jbF3jb?F3jbF3ibG3gbA3gbD3pbV5j[/fumen][fumen]110@lcC3jbF3jbF3gbsshbF3usG3gbB3gbC3HcC3jbF3jb?F3jbG3ibF3gbB3gbC3pb15j[/fumen][fumen]110@lcC3jbF3jbF3gbsshbF3usH3gbA3gbC3HcC3jbF3jb?F3jbG3ibF3gbA3gbD3pb15j[/fumen][fumen]110@lcC3jbF3jbF3jbF3hbA3gbF3hbE3HcC3jbF3jbF3hb?YigbF3gbA3YigbH3ZiC3pbeMj[/fumen][fumen]110@lcC3jbF3jbF3jbF3ibG3hbE3HcC3jbF3jbF3hbYigb?G3gbYigbH3ZiC3pbeMj[/fumen][fumen]110@lcC3jbF3jbF3jbF3jbG3gbE3HcC3jbF3jbF3gbZigb?F3hbYigbH3YiD3pbOMj[/fumen][fumen]110@lcC3jbF3jbF3jbG3ibF3hbE3HcC3jbF3jbF3hbYigb?F3aiI3hbC3pb2Mj[/fumen][fumen]110@lcC3jbF3jbF3jbG3ibF3gbB3gbC3HcC3jbF3jbF3hb?YigbF3aiG3gbB3gbC3pb2Mj[/fumen][fumen]110@lcC3jbF3jbF3jbG3ibF3gbA3gbD3HcC3jbF3jbF3hb?YigbF3aiH3gbA3gbC3pb2Mj[/fumen]

I's
Since an I can solve any case, they're the best ones to hold, all other things being equal. The only other thing worth noting is the vertical solutions.
[fumen]110@lcC3jbF38eibF38eibF38eibF38eF3HcC3jbF3ib8e?F3ib8eF3ib8eI38eC3pbA4G[/fumen]
This solution is useful when you run into these traps where you don't get an O tetromino soon enough:
[fumen]110@tbA3kb/eA3kbE3cdC3jbF3jbF3jbF3jbI3gbC3pbmZ?I7eBsgBSiqJAOH98AwW88ARAAAA[/fumen]
Instead, use this:
[fumen]110@pbIwibA3kbKwgbA3kbE3cdC3jbF3jbF3jbF3jbI3gb?C3pbJVIzboUQpnb4GpUaeWmB7eAShBHcxNobxNGeM8c7eBE?hBAAA[/fumen]

Zigzags and O's

The pieces I find myself "deadending" on the most are the zigzags and O's (especially when they're close together in the queue). That's why I find it useful to identify them in the next queue and work out a plan before they come up.

This particular case can cause problems. You need either an O or the correct gun (L or J) to go along with it.
[fumen]110@5cC3jbF3jbF3hbA3gbF3hbE3HcC3jbF3jbF3gbA3hb?H3hbC3pbA4G[/fumen]
So try to avoid creating it if you see you don't have an O or the corresponding gun:
[fumen]110@tbA3obA3kbE3cdC3jbF3jbF3jbF3jbF3gbF3pb1CH7?eBsgBSdqYANwceEFbkzDBSVTASIiSASIiXEFbUOC[/fumen]
Instead, create a different, more welcoming formation:
[fumen]110@tbA3obA3kbE3cdC3jbF3jbF3jbF3jbF3gbF3pbtYI7?eCkhBaiBAAA[/fumen]

This can end your combo:
[fumen]110@/dC3jbF3jbF3jbH3hbG3ibC3pbnZI7eAEoc[/fumen]
So do this instead:
[fumen]110@/dC3jbF3jbF3jbH3hbG3ibC3pbPaI7eCM8cEhBAAA[/fumen]

And instead of this:
[fumen]110@tbA3obA3kbE3cdC3jbF3jbF3jbG3ibH3hbC3pbr9G7?eA2hB0bNRnbNRBe1lnb1lsbnKA7eBsgBSnqKAk4znDFbcpD?OnBAA[/fumen]
Do this:
[fumen]110@tbA3obA3kbE3cdC3jbF3jbF3jbG3ibH3hbC3pbjZI7?eEWQAPhBkhBaiBAAA[/fumen]

This shape is usually very welcoming:
[fumen]110@5cC3jbF3jbF3jbI3gbC3HcC3jbF3jbF3jbF3gbF3pb?A4G[/fumen]
...but it can cause problems when zigzags are coming:
[fumen]110@tbA3obA3kbE3cdC3jbF3jbF3jbF3jbI3gbC3pbmZI7?eCChBPiBEyc[/fumen]
In this situation, this would work better:
[fumen]110@tbA3obA3kbE3cdC3jbF3jbF3jbF3jbI3gbC3pb2CHp?b4Gob6GkeaiBgeIwobKwtbAAA7eCPhBkhBAAA[/fumen]

T's and Guns
Don't create this shape unless you have either a T or the corresponding zigzag or gun:
[fumen]110@5cC3jbF3jbF3jbH3gbD3HcC3jbF3jbF3jbG3gbE3pb?A4G[/fumen]
It causes deadend piece combinations.
[fumen]110@ecIwobKwtbC3RphbF3gbRpgbF3jbG3gbE3ubYimbai?tbC3gblzgbF3lzhbF3jbH3gbD3pbA4G[/fumen]
For example,
[fumen]110@tbA3obA3kbE3cdC3jbF3jbF3jbG3ibH3hbC3pbrZI7?eAEYqOA3rDKEnoo2A6eRyEhrBAA[/fumen]
You might do this instead:
[fumen]110@tbA3obA3kbE3cdC3jbF3jbF3jbG3ibH3hbC3pbj9G7?eCkhBmhBAAA[/fumen]

As I mentioned before, the flat 3-in-a-row case usually is pretty flexible, but you still have to pay attention:
[fumen]110@tbA3obA3kbE3SdC3jbF3jbF3jbF3jbF3jbI3gbC3pb?H+G7eERhBmhBsgBqhBAwNKAE4znDFbcpDOnBAA[/fumen]
You can allow for those pieces by using the vertical I-tetromino instead:
[fumen]110@tbA3obA3kbE3SdC3jbF3jbF3jbF3jbF3jbI3gbC3pb?H+G7eBJdBGhB/bdDmbdD2dlzmblzubEQA7eBChBAAA[/fumen]


Those are just a few "for instances" that I found useful. After enough practice, you begin to get a feel for what will work and what won't.

Combo prep stacking

There must always be three "minos" in the 4-wide well--not 0, 1, or 2. To do this, you put 3/4ths of a piece in the 4-wide area from the start. I prefer to use a zigzag, but there're pros and cons of each opening, I guess.
[fumen]110@bcJwQpjbC3IwRplzhbC3IwQplzibC38b8eC3kbss8e?C3hbRpts8eC3ibRpss8e9bKwjbC31lIwlzhbC31llzibC3p?bA4G[/fumen]

There are many possible combinations available to us when building or 3-wide side stacks. These are just some examples:
[fumen]110@1bQplbQpYiRpjb8eRpYiQp8ejb8eRpZi8ejb8eRp1l?8ejb8eQpYi1l8ejbaipbJwQpjbLwRpjb1lJwQpYijb1lbij?baiqblzjb8eQpgblzYijb8eRpaijb8eRpmb8eRpYikzkb1l?QpYilzjb1laikzjbaipbA4G[/fumen]

Handling T's
With regards to the 3-wide stacks, we need to pay special attention to T's. In short, if we put a T on one side, then we need to stick the next T on that same side. T's change the dynamic of the stack and make it harder to deal with. So instead of "T-ifying" both the left and right stacks simultaneously, it's best to instead T-ify one stack and then use the next T to un-T-ify it. Why are T's special like this? Maybe it's because they have a strange property that differentiates it from the other pieces. If you put all the tetrominoes on a checkerboard, you'll find that they all have two dark "minos" and two light colored ones... that is, except for the T.
[fumen]110@3bssnbssA3sswbA3obIwA3IwybA3mbYiA3YiwbQpA3?obQpA3xbkzA3mbkzA3xb8eA38eA3wbA30lnb0lA3tbAoUuA?lRNXE5XprDFbkzDhN98AwH7rDuoo2AD9kkDrICbEFLHSAS4?MhE0oo2A0VAAA[/fumen]

Fill it in later
Sometimes we'll find it necessary to leave vacant spaces in the stack and fill them in later.
[fumen]110@jcQpnbRpssmbQptsailbssYimb1lIwmb1lKwtbcikb?Yi1laikb1lZimbsskzYilbtslzkb1lssIwkzkb1lYiKwjba?ipbA4G[/fumen]

Toss it
If we can't place a piece in the 3-wide stack without it causing an extremely unstable stack and/or hole, then it's usually best to just toss it in the 4-wide stack until the 3-wides stabilize. Make sure you drop it in a way that doesn't lead to a deadend. Also, try to resort to this as little as possible.
[fumen]110@fdA3obA3gbA3gbA3kbC3gbA3kbE3jbF3jbF3jbH3hb?G3ibC3pbHPwDAl8VBA7eAnRPMAUnEbEFb82D0oA6A[/fumen]

That's all for now. Good luck! By the way, I'd be happy to add any examples that you guys come up with to this post later on if you like.

* Here is the orginal link. I used the imgur one above, so as to save the host a little bandwidth.

[Lucho]

Very helpful, is appreciated

[DarthDuck]

When stacking to the sides it's important to keep the blue pieces under red ones and orange pieces under green ones. If you do it the other way around then you get T-ified as Caffeine puts it. That means you end up needing to dump lots of blocks in the center which will slow everything down and require more overall building.


[fumen]110@7eOycIWoB3aBUeB5UBNVBzTBXKBCFBdRBWABTGBmBB?y8AymB[/fumen]

It's usually a good idea to wait for the red and green pieces in situations like this. That will often mean sacrificing one side or the other for the sake of Os, Ts, and Is. As long as you don't gunnify the guns on both sides, then being able to put a zigzag in at least one or the other will make it easier to avoid overreliance on the Is.


edit:

This is the thing that almost always messing up my center 4-wide stack, requiring me to start the combo early or throw away pieces in the middle!

[randomtetrisnoob]

Handling T's
With regards to the 3-wide stacks, we need to pay special attention to T's. In short, if we put a T on one side, then we need to stick the next T on that same side. T's change the dynamic of the stack and make it harder to deal with. So instead of "T-ifying" both the left and right stacks simultaneously, it's best to instead T-ify one stack and then use the next T to un-T-ify it.

This is awesome!
This is the thing that almost always messing up my center 4-wide stack, requiring me to start the combo early or throw away pieces in the middle!

I always somehow "knew" this subconsciously, that somehow I always knew that the stack became a "problem stack" whenever it had a certain shape (that is usually caused by a T), but I never really pinpointed it like this!
Thanks a lot!

[Ravendarksky]

When I went for my 100 combo dig I found holding the O piece to be equally or more useful than an I piece.

This is because mostly I die  due to streams of Zs or Ss and Os save you the best from this. Also I find there are loads and loads of combos which allow a nice balance of pieces but rely on an O.

This probably isn't that useful for people who want to master 4 widing but it is certainly useful for lazy people like me

[caffeine]

This is awesome!
This is the thing that almost always messing up my center 4-wide stack, requiring me to start the combo early or throw away pieces in the middle!

I always somehow "knew" this subconsciously, that somehow Ir always knew that the stack became a "problem stack" whenever it had a certain shape (that is usually caused by a T), but I never really pinpointed it like this!
Thanks a lot!

Glad I could help!
@ThatsSoRavendarksky That's interesting. I'll definitely try this out.

[DarthDuck]

When I went for my 100 combo dig I found holding the O piece to be equally or more useful than an I piece.

This is because mostly I die  due to streams of Zs or Ss and Os save you the best from this. Also I find there are loads and loads of combos which allow a nice balance of pieces but rely on an O.

Interesting indeed but if you see an O coming you usually get rid of it right? In ZeroTs commentary during his video he warns about double-Os and I agree that I've had many deaths because of it.

[Pheeb]

Just wanted to say thank you for this wonderful piece of work.  Clearly, you spent a lot of time on it.  I plan to study it in detail.  

Thanks

[Ravendarksky]

Okay I've got some time to elaborate on what I was talking about....
For us lazy 4-widers the hardest piece to manage is the S or Z. More than one of these coming near each other is sure to end your fun!

Rather than learn to 4wide perfectly... I just try and make sure that I have as many escape routes as possible from S Z death. This basically involves trying to use these pieces as soon as I get them and chain the other pieces around them. This is why I love the O piece so much!

[fumen]110@9bC3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jb?F3jbF3jbF3jbF3jbF3jbF3jbF3jbI3gbC3pbAoUNAJoo2As?X7rDFbMfCTBAAA7eKPiB7gBaiB7gBshBHhBugB7hBFhBfiB?7gBpbC3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jbF3?jbF3jbF3jbC3ecMRss8eA3sbAwNiAhideD5N98AQGdrDFbE?cEvoo2A0nrTASoFeDuW98AQXBAA7eMAwNJAvb88Awc88ARA?AAAAwNFATH98AQAAAAugB7hBfhBkhBfiB7gBdiBHhB8gB7h?BAAA[/fumen]

So I guess what I'm saying is.... If I can see one of these setups coming up where an O allows me to make a shape where I can burn an S and Z OR if a shape is coming up where an O will save me from these, I prefer to hold the O and burn the I

Just did an 84 combo to test this

Anyone got any good advice for 4 wide building?

L and J fixes can be done quickly with rotating the correct way.... doesn't look like it would work but it does:

[fumen]110@WdA3nbB3gbA3kbE3kbD3lbE3kbE3kbF3jbF3jbI3gb?aipbKpj7eJy2caRBAAAO8AKicyncaCBAAATxAt6A0bA3nbB?3nbC3mbC3mbB3nbB3nbB3nbB3nbC3obA3Kd5Gc7eBZkAAAA?[/fumen]

[myndzi]

I second the "identifying bad sequences and working around them" - though I haven't spent much time at it. Since certain pieces/sequences decrease your flexibility - or the paths to success - it is important to accommodate them as soon as possible in order to widen up your possibilities again. If you are stuck holding a piece that can't be used well, you are essentially forced to play without the benefit of hold. It's interesting to see the possibilities for O laid out like that, too.

As for the L-fix, I rotate the other direction:
[fumen]110@WdA3nbB3gbA3kbE3kbD3lbE3kbE3kbF3jbF3jbI3gb?aipbKpj7eCixc6xcaxc[/fumen][fumen]110@WdA3nbB3gbA3kbE3kbD3lbE3kbE3kbF3jbF3jbI3gb?aipbKpj7eCyxcy2c6mqLAOH98AQGTtCFrmAA[/fumen]

This gives gravity only one rotation to interfere, and you don't need to DAS to rotate the piece into place, just tap once to shift.

If anyone cares, I've noticed some interesting dynamics with the 0-residue 4-wide stacking, including some much more useful properties of the O piece, as well as S/Z pieces, but the 3-residue is definitely easier to pull off. I'm not entirely sure, but I think 3-residue is more stable after playing around in combo race for a while.

Decided to do up a little something with 0-residue anyway. You can see some useful shapes pretty easily here, and you can see that there are some quick transition possibilities to handle upcoming pieces. It looks like there were some sequences where I had to use hold a lot, which would indicate longer sequences with few possibilities, but I generated the pieces randomly and only backtracked twice to solve this entirely - and I don't practice 4-widing at all, certainly not this way. I just always liked some of the moves

[fumen]110@pbC3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jb?F3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jbF3hbA3gbF3gbF3p?bAoUuA08taEFb82Dzoo2Ahoo2AoCRoD5oo2AT9TQEloo2AJ?G98AQoNVElNGoD1oBAA7eR8QPfADCpTASY6dDOnkrDFb8bD?MPNXEuiW5Du788AwsDCAfSPLA3u+1DFbcpDhNdCA8gBAwNZ?AUoo2AD9jJEnY0TASY91Dloo2AT9TQEFBAAAdiBWRPAAyhB?tgB8hBfhB/hBdiBuQPeAzOckDroSTASIyZEFbsiDBG98AQz?UTASozdDzGCAAzMPAAzbB8hBahBzcB9bC3jbF3jbF3jbF3j?bF3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jbC3?Hc8gB7eCuhBzbBdiBHcC3jbF3jbF3jbC3ddUKmbwN4GUKsb?AwNbAMo2TAySzTASYtXE5oo2AzHnrDFbUfDhb8CA7eMAwNj?APAGDEavceEqekNEazuyEqNGDEPweDE6nU5DMAONE0dMDAz?RPiAqucyE09u8DptjyEMf88DzuUNEK/cyEvNGDEqeTeETIC?AAeRPhAJTseETfA5DzXsDEUowaEJjj8DUT0NEzuc8Dp3GbE?aBAAA5LPgAMIHbEUAuaEPINeEagU5DsXIeEM47aEJTA5DPv?syE0RPlAFbWBEFrYcETfA5DzXsDEUowaEJjj8DUT0NEzuc8?Dp3GbEaBAAAdSPkAFbWBEFrAZEUAuaEPINeEagU5DsXIeEM?47aEJTA5DPvsyEfRPjAFbWBEFrYcEqekNEazuyEqNGDEPwe?DE6nU5DMAONE0dMDAyRPiAFbWcEFro6DptjyEMf88DzuUNE?K/cyEvNGDEqeTeETICAAuRPhAFbWcEFrQ3DzXsDEUowaEJj?j8DUT0NEzuc8Dp3GbEaBAAAdRPgAFbO3DFrAZEPINeEagU5?DsXIeEM47aEJTA5DPvsyE5LPfAFb+YEFrgLEazuyEqNGDEP?weDE6nU5DMAONE0dMDAzRPeAFb+YEFrowEMf88DzuUNEK/c?yEvNGDEqeTeETICAAcRPdAFb+YEFrYBEUowaEJjj8DUT0NE?zuc8Dp3GbEaBAAAlcC3jbF3jbF3jbF3jbF3jbF3jbF3jbF3?jbC3lcaSPcAFb+YEFrYcEagU5DsXIeEM47aEJTA5DPvsyE7?eIPRPbAFbWcEFrowEqNGDEPweDE6nU5DMAONE0dMDA1RPaA?FbmwEFro6DzuUNEK/cyEvNGDEqeTeETICAA8QPZAFbm6DFr?AZEJjj8DUT0NEzuc8Dp3GbEaBAAAfSPYAFbm6DFrQ3DsXIe?EM47aEJTA5DPvsyE5LPXAFbm6DFrYBEPweDE6nU5DMAONE0?dMDA2RPWAFbWBEFrgLEK/cyEvNGDEqeTeETICAAzMPVAFbW?BEFro6DUT0NEzuc8Dp3GbEaBAAAqLPUAFbm6DFrYcEM47aE?JTA5DPvsyEmRPTAFbWcEFrYBE6nU5DMAONE0dMDAHcC3jbF?3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jbF3jb?C3RcNRPSAFbWBEFrowEvNGDEqeTeETICAA7eMaSPRAFbmwE?FrgLEzuc8Dp3GbEaBAAAzLPQAFbmwEFrAZEJTA5DPvsyE8R?PPAFb+YEFrQ3DMAONE0dMDA5LPOAFb+YEFrYBEqeTeETICA?AiRPNAFb+YEFro6Dp3GbEaBAAAuRPMAFb+YEFrQ3DPvsyER?MPLAFb+YEFrgLE0dMDAzLPKAFb+YEFrYcETICAAdSPJAFb+?YEFrAZEaBAAAfRPIAFb+YEFrowE8RPHAFb+YEFr4AAfRPAA?AAA[/fumen]

One obvious advantage to the 0-residue 4-wide is that all the placements are hard drops - there are no twists. This could be a disadvantage in allspins, I suppose, but the number of spin non-mini singles available is few (unless 3-point, perhaps).

[Ravendarksky]

Um Sorry I guess I didn't explain it right.

[fumen]110@XdB3nbB3nbB3nbB3nbA3obB3nbB3nbC3mbC3wbKAxL?Ao3MoDFbEmDvjxCA7eDKmqdAo3MoDFbEBEFq2TASoiJEkoo?2AQMlaEzoo2A4AAAAy7caWBAAA[/fumen]

I don't know how it works but it does =D

[xbxcv]

any tip in stacking im finding it diff (

[electrofry]

" the zigzags and the O's"

the zigzags? xP

[caffeine]

" the zigzags and the O's"

the zigzags? xP

Sigh... fine. I won't use "zigzags" or "guns" anymore. What do the cool kids think would be a good choice for collectively referring to either Z/S or J/L, then?

[Sisu]

http://www.cs.carleton.edu/faculty/dlibenn...etris-short.pdf

snakes?