A T-spin is a move where the T piece is dropped into a slot, rotated into place, and then is locked in without any more movement.
If the T-spin clears 0 lines, it is called a T-spin zero. If it clears 1 line, it is a T-spin single. If 2 lines, it is a T-spin double. If 3 lines, it is a T-spin triple.
For more differentiation between types of T-spin, for example T-spin Mini and EZ T-spin, see the afterword in this chapter.
T-spin Double Guide
T-spin doubles are by far the most commonly used types of T-spin in the modern game (discounting Tetris Friends Marathon, where T-spin Triples and Singles are more useful), because they are simple to think about and execute compared to T-spin triple, and they are rated as having as much power as a Tetris in guideline games. For example, in multiplayer modes, a T-spin sends 4 lines, and 5 (or 6 in Tetris Battle on Facebook - which from now on I will simply call Tetris Battle.) when back-to-back bonus is on, which is exactly the same as what a Tetris sends, but in half the number of lines, making them a very powerful tool. It will start and continue back-to-back bonus. When combined with Tetrises, they can double your attack potential, because now twice in each bag you can send large numbers of lines, instead of just once.
To do a T-Spin Double, you need to look for a T-hole in your stack. Sometimes these will be easy to spot, and other times more advanced sight will be needed to place pieces in order to develop the T hole. There are two basic shapes: The upside-down T, and the single gap. The upside-down T is just what it says: an upside-down T in the stack, ready for an overhang to be placed straight on it, leading to a T-spin double. These are the first 4 diagrams. The single gap is also what it sounds like: a gap one hole wide in the stack. The crucial thing about the single gap is that its sides have equal height with each other. If they do not, then extra pieces will be needed to equalise the heights of the sides. Examples of the single gap are the next four diagrams. See below:
The next step is making the overhang. To make the overhang, you need to think of which piece would be used to make the T-hole more closed, such that the T can no longer be hard dropped in, but only soft dropped and rotated. To work out the right piece to use for the overhang, you need to look at the height of the stack to the sides of the T-hole. Usable heights of surrounding stack range from 2 above the top of the T-hole (it will look like a stack 3 blocks high), which only a J or L will work with, hanging off the edge, to 2 below, where only a J or L standing up will be able to create the overhang. Any higher than 2 above and you need to clear down lines before you can make an overhang for the T-spin. Any lower than 2 below and you need to insert an upright I piece to create the overhang. Here are a copious set of diagrams showing most possible overhang combinations of pieces and heights of stack (and all of them can be worked out from this set).
and the same but with the L (orange) piece.
Note the special case of the upright S and Z, which can be placed even without stairs - they initially create a hole in the stack, but the T-spin clears the hole immediately.
A good T-spin player will know all of these intimately, but you don’t need to go and learn them off by heart; through experience you will soon become acquainted with all of them, however far off that may feel at the moment. Another way to see where to place the overhang is imagine the T piece in the spot you want to spin it into (where I put the green ticks in the earlier diagrams), and then imagine the overhang as touching the top of one of the right or left arms of the T, but not blocking it.
To perform the T-spin, all you need to do is rotate the T into sideways position, soft drop the T into the hole, rotate it into position, and then press the hard drop button to lock it down.
Quick tip: You can get the T-spin double out quicker in games without sonic drop (all guideline games) if you use a wallkick to spin the T in. Instead of having to soft drop the piece all the way into the hole, you have to soft drop it in 1 block less far. However, this works only if there is a 2 block high wall which the T can kick off. See the diagram below for details:
Once you have done the T-spin double, you will want to learn how to string them together. The way to do this is by good management of the stack, as well as knowledge of skimming and clearing patterns. What you want to do is leave the single gap which we were discussing earlier, where each side of the single gap is the same height as the other. The stacking, clearing and skimming patterns to flatten the sides of the stack are very similar to the overhang patterns seen earlier. See diagrams below for ways to change different sides of the stack (note that the numbered blocks are there to demonstrate the difference between the left and right side of the stack - they denote existing blocks on the side of the stack which they appear at:
Note that these methods of remaking the single gap for the T-spin are very powerful, because, with some foresight, you are able to place an overhang over the hole which will become the T-spin, thereby increasing efficiency of pieces. See below for some examples of 1, 2, and 3 difference stacks being converted into T-spins after the overhang has been placed:
Such types of T-spin where the overhang is placed before the T-hole is created are called prophecy T-spins. The most common type of prophecy T-spin is where the hole for the T is under some garbage, and you need to clear through the garbage before it becomes a T-spin. But with some foresight, the overhang has been placed before the garbage has been cleared. See this diagram for details:
From a blank field situation, the way to start doing T-spin doubles is either to learn static T-spin setups, especially the TKI-3, or to stack blocks with the aim of building the single gap with equally high sides. Then you are ready for the overhang to be placed, and for you to T-spin.
To many very experienced T-spin double players, the T-spin Triple is still territory which they have not fully explored yet, or got down to such a comfortable extent that they can play it reasonably regularly when they choose to do so. However, it is the most powerful move in the game in terms of lines sent (except for Perfect Clears in Tetris Friends and Tetris Battle), and can lead to extremely quick KOs of opponents. It sends 6 lines without back-to-back bonus, and with back-to-back bonus it sends 7 lines in Tetris Friends, 8 lines in Tetris Online Japan (and games in imitation of this), and 9 lines on Tetris Battle. It is riskier than the T-spin double, and less suited to downstacking due to its residue lying over the downstack hole when played directly over the hole. However, when it is used as an attacking option when the opponent is pressured and not sending you lines it can be devastating. It is also the only way to get world-beating scores on Tetris Friends Marathon mode.
The basic T-spin Triple shape is a C shape, 3 blocks high and 2 blocks wide. Once this shape has been made (and assuming there are no blocks directly above it), it is a trivial matter to place the overhang and execute the spin. Here is a diagram of the shape below. It relates to the T-spin Triple like the upside-down T hole relates to the T-spin Double.
Why no blocks can be put directly above the C shape:
On a related point, often new players wonder whether they should put the stack and overhang directly in front of the C shape or 1 away. The correct way to do it is 1 away, and anyone who has made the mistake of putting the overhang directly in front of the C shape has realised this after the bad experience of scuppering their T-spin Triple.
So the C shape cannot be touched on the top or on the open side. However, it can be touched on the closed side and on the bottom.
To create the overhang, you need to place a mino two blocks higher than the T hole (see the diagram below showing the T-spin Triple method for visual guidance on where the overhang should go). It should come from the stack opposite the C shape, and not from the C shape, or you will have the error shown later where the overhang goes the wrong way and you cannot rotate the T piece in. See the section on overhangs for T-spin Doubles for how to make a T-spin Triple overhang; the same method of finding how far above or below the T hole the stack opposite the C shape is also works here.
The method to do a T-spin Triple: Soft drop the T, slide it into position, rotate it in, and then hard drop to lock the piece down. If the hole is facing left, as it is in the diagram below, rotate anticlockwise. If it is facing right, rotate clockwise.
Another trick is to visualise the situation where you have to rotate the T into the position directly before rotating the T into the T-spin Triple hole. If you rotate it the same way both times, you will do it right. So if you imagine you are rotating the T into position even when you are sliding it there, you will always find the correct rotation. Note that you need a 2-high wall at least to get the wall kick to spin the T into position in this way.
Note also that the overhang must go the correct way. If it goes the wrong way, the T will not be able to rotate into the hole. This problem affects many players starting to learn how to T-spin Triple. The way to visualise where to put the overhang is that the tip of the overhang should go the same way as the tip of the T-spin Triple hole. Or you could see it as an extension of the rule “nothing can touch the C shape” - by placing the overhang as below, you have touched the C shape on the top and the T-spin Triple won’t work. So in the diagram above, the hole is facing left, and so is the overhang. See this diagram for what happens when you get it wrong:
There are four main ways to set the C shape up for the T-spin. One is the single block, another is the steps method, another is the lying down S/Z method, and the last is the flat I/J/L method.
The single block in the T-spin Triple is directly comparable to the single hole in t-spin doubles. It is the most basic stack shape to look for when going for a T-spin Triple. It is a single block, whose sides are not touched by any other blocks, and whose top is not touched by any other blocks. It looks like this (not that it’s a good idea to make a T-spin Triple in every situation you encounter the single block - the advanced situation below would lead to a tricky stack to make the overhang out of, for example. However, it is always good to spot the possibility of making one.
To make the C out of the single block, just place an L or J piece upright directly to the right or left respectively of the single block. Then make the overhang, and a T-spin Triple is yours. See diagrams below:
As the name suggests, this method is done by spotting an upside-down T shape in your stack, which will look like a 2 block high set of steps. Note that it doesn’t have to be a literal T piece; just a shape which corresponding to an upside-down T. Then place an L or J flat face down with an overhang on the steps. One could see it as an extension of the single block, as at the top of the stairs there is a single block, but the stair shape makes it possible to build the T-spin Triple one row lower than if the L or J was placed upright as in the single block method. See the diagrams below for more information:
This is possibly the simplest method to make a T-spin Triple: Find a flat surface which ends, and then place an S or Z piece flat on the surface with the point directly above the block of the surface closest to the end. That’s the C shape made.
Note that this setup can give you a T-spin Double - it is the same Z position as the one in the first T-spin double in TKI-3, where it is used as an overhang.
The last easy way is if you see an at least 2-high surface with a stepped incline, you can put an I, or a J or L (depending on the way the surface faces) flat to make the C shape. If you use a J or L, you need to cover its tip, otherwise you will not be able to twist the T into position (shown above - the wall to twist from is not 2 blocks high)
The rest of learning to do T-spin Triples is just learning to spot these shapes with which one can make the C shape. Experienced T-spin Triple players will also know how to make the shapes above such as the single hole, or the slanted edge in preparation for T-spin Triples. Finally, it will help to learn a few of the setups later in this chapter, which can give multiple T-spin Triples.
What I said at the start of the T-spin Triple guide holds even more for T-spin Singles, Mini Singles and EZ Singles; only the absolute top players will be able to get the most out of them. They are easier to spot and to execute than T-spin Doubles and T-spin Triples, but because they can be done so often, and because they are not the centrepiece of an attack quite like Tetrises, T-spin Doubles and T-spin Triples are, they are often overlooked. A T-spin Single sends 2 lines, and 3 with back-to-back bonus on. A T-spin Mini Single sends 1 line in Tetris Battle and back to back it will send 2 lines, and likewise on Tetris Online Japan (and modes in imitation of this). It sends no lines in Tetris Friends. As a subset of the T-spin Mini, the EZ T-spin has the same lines sent values. In every game, all three start and continue back-to-back bonus.
There are only two types of T-spin Single which should be made on purpose; all the other types are due to unfilled lines where the T piece could have made a T-spin Double or a T-spin Triple. Both are Mini Singles, so they have limited use in Tetris Friends (they only set back-to-back on), but they are very useful in Tetris Battle and Tetris Online Japan (and TOJ imitation games). When used correctly, they can be very useful in Tetris Friends as well.
The kicked T-spin Mini Single is often used as an opening move on Tetris Online Japan (and TOJ imitation games) due to its ease to set up, and the clean field it leaves. However, it is also used often midgame, since it is easy to set up and execute.
To see it midgame, just find a wall at least 2 high with a flat area at least 3 blocks wide.. Then put an overhang 2 blocks away from the wall, and then spin the T into the hole. The rules of overhang still work with this setup. See diagram below for details:
Note that there cannot be a hole under the column adjacent to the wall you will be kicking the T-spin off, or else it will simply count as a single:
The EZ T-spin Single is a subset of the T-spin Mini Single. EZ is shorthand for the word ‘easy’, because they are easy to spot, easy to perform, and since the piece could have been hard dropped into the hole without needing to be spun, they seem too easy to count as anything. However, they are one of the most powerful moves in the game for people who know how to use them. They are always worth doing wherever you see the chance to do them in Tetris Battle and Tetris Online Japan (and modes which imitate it). However, in Tetris Friends it is only worth doing them if you think you will directly afterwards score a Tetris or a T-spin (which isn’t a Mini), since they send no lines but activate back-to-back bonus. Seeing and performing EZ T-spin Singles in the most efficient way is what separates the truly great players from the merely good players.
To perform an EZ T-spin Single, you need to look for a 1 wide hole next to a wall at least 3 blocks high (i.e. at least the same height as the upright T when in the hole), and a flat space at least 2 blocks wide away from the hole. Then soft drop the T face up next to the hole, and then rotate into the hole. Then hard drop to lock it into place.
Its power also lies in the stair shape it leaves behind, perfect for a quick T-spin Double. When done over a long hole 2 high or more, it is called the Yoshihiro T-spin Double setup. This will be covered in the setups section later, but it is also in the diagrams below.
To do an EZ T-spin Single, as I stated earlier, the wall which the T piece’s back is facing must be at least 3 blocks higher than the single hole. Otherwise, it will count as a normal single, not a T-spin Mini Single. The spin will work, since it is a result of natural SRS patterns, but it just won’t score in the same way.
Of course, to set up the base for an EZ T-spin Single, you need to look for a hole and either a wall at least 3 high, or a 2-wide flat area around the hole. Then you can set up the other one (a 2-wide flat area or a 3-high wall respectively) and do the EZ T-spin Single. To make the whole of a setup, look for a part of it already in the stack, set up the other part, and then complete the whole. With that said, let’s go onto static setups.
Afterword - Technical points and spin rule systems: 3 Corner/4 Point vs immobile, T-spin Min and EZ T-spin, ARS T-spins vs SRS T-spins vs other rotation T-spins.
A T-spin move will count as a T-spin if three of the four spaces diagonally adjacent to the centre of the T piece are filled, under the 3 Corner T rule, also known as the Four Point T rule, used in all guideline games, and all non-guideline games which aren’t all-spins. See this image for explanation of the Three Corner T rule:
The blocks with ticks on them are the three spaces diagonally adjacent to the T-piece which are filled in by other blocks, which make this placement a T-spin. The fourth with a cross on it is the other space diagonally adjacent to the T-piece which is not filled by other blocks.
In Immobile spin rules, which are used in all-spin modes, as well as The New Tetris, the only requirement for a spin to count is that after the spin, the piece cannot be moved left, right, or up, even after any number of rotations. See the following diagram for details:
The spaces with crosses in them are to demonstrate that it is impossible for this T-piece to move up, left or right in its current position. Note that under Three Corner rules, this would not count as a T-spin, because two of the spaces adjacent to the centre of the T-piece are left unfilled.
T-spin Mini is a category of T-spins which in guideline games earn less than standard T-spins, but still are counted as T-spins. There are three rules to determine whether a T-spin counts as a T-spin Mini for Tetris Friends - other games may and do vary:
1. There is an open corner on the point-end.
2. It clears one line or fewer.
3. It did not reach its final position by means of the T-spin Triple wall kick.
An EZ T-spin is a type of T-spin mini which is distinguished by the fact that the piece would have been able to be hard dropped into the position without using the wallkick which activates the T-spin. They count as T-Spins under 3-point rules, but not immobile rules, since after being rotated again, the piece is mobile. See the next set of diagrams for how to do an EZ T-spin:
In Tetris Friends Arena, they do not send any lines, but they do activate back-to-back bonus. In Tetris Battle and Tetris Online Japan, they send one line as well as activating the back-to-back bonus.
 Information shamelessly ripped from http://kitaru.1101b.com/writings/tetris4.html