From Hard Drop Tetris Wiki
Dragonbucket (or simply 'Bucket') is an MTD opener (TSM→TST→TSD) for early S/Z bags. Notably enough, the T-Spin Triple and the T-Spin Double setups in the second and third bags have no dependencies, so they can always be stacked. A T-Spin Double can always be performed in the fourth bag, and, depending on the pieces used for the T-spin, there is a high chance for a Perfect clear in the fifth one or another TST. This opener was discovered by J4den Ryu.
Overview
The discussion below will assume that the 'bucket' (the LJ shape) is placed on the left side of the board.
1st bag |
2nd bag |
3rd bag |
4th bag (L>Z) |
5th bag (89.72% PC or... |
100% TST!) |
1st bag |
2nd bag |
3rd bag |
4th bag (Z>L) |
5th bag (99.40% PC or... |
80% TST!) |
1st bag (for b2b) |
2nd bag |
3rd bag |
4th bag (Z>L) |
5th bag (100% TSD or... |
66.67% TST!) |
First Bag
The setup rate is 70% if both orientations are considered and 50% for one side only. Either S or Z before I and O are required to build the first bag, so this setup fits very well if combined with setups like SingleYou and TKI 3 Opening together. It is recommended to use this opener if both S and Z come before the I and O pieces so that you can place the Z piece first if possible (on top of which you don't place the I and O-piece), as this will ensure hard dropping all the other pieces (except for the T-piece, of course) and allow you to move quickly to your second bag.
Normal form |
Normal form |
Normal form |
The first bag can also be built differently (we call it 'variant form') by placing the I piece within the bucket on top of the J piece. It works for early JIS bags, but it is also recommended to build this setup if the I piece arrives late in the bag, although it can be quite risky. Doing so removes the sensitivity to garbage received (in multiplayer games) during the second bag (where one would place an I piece anyway) but sets a dependency between the S and I pieces (I>S in the second bag). You can safely use the variant setup if you see the I piece before the S piece in the second bag while building the first bag.
Variant form |
Variant form |
Variant form |
The setup rate of the variant form is 61.90% if both orientations are considered and 43.33% for one side only. If one combines the variant setup with the normal one, the cover rate of building one of the two setups slightly increases to 75.71%. If one sacrifices the TSM by placing the T-piece before clearing any line, then the setup rate becomes 89.37%.
Second Bag
Normal route
The second bag can always be stacked like this if there is no hole (due to the garbage sent from your opponent) in the third column from the left (if a hole appears at that point, see the 'Garbage routes' below).
|
|
|
|
8L PC routes (late OS bags)
Alternatively, one can aim for an 8L PC (medium chance) if the O and S pieces come late in the bag (it happens 14.29% of the time). In one case, you can place them as shown below:
- 8L PC route-1
8L PC route-1 |
8L PC route-1 |
8L PC route-1 |
47.62% PC |
This PC success rate with this setup is 47.62%, which is not high. However, you should be able to see some pieces of your next bag while deciding how to place the O and S piece. You can tell beforehand if you will succeed in performing a PC before placing them in the way shown above or abort the setup and stick with the normal route. If you see T and S pieces within the first three pieces of the next bag, then there is a 91.67% chance of a PC and a 100% PC chance if the first three pieces are TSL or TSJ (in any order). Below are shown all the solves:
8L PC route-1 solve |
8L PC route-1 solve |
8L PC route-1 solve |
8L PC route-1 solve |
Next, we show the second way one can place the O and S piece if they come late in the bag:
- 8L PC route-2
8L PC route-2 |
8L PC route-2 |
8L PC route-2 |
29.88% PC |
This PC success rate with this setup is 29.88%. Here also, some foresight is needed in order to decide if it is worth taking this route. If you see T and O pieces within the first three pieces of the next bag, then there is an 85% chance of a PC and a 100% PC chance if the first three pieces are TOL (in any order). Other first-three-piece bags like TOJ or TOZ will lead to a 91% PC chance. Below are shown all the solves:
8L PC route-2 solve |
8L PC route-2 solve |
8L PC route-2 solve |
Garbage routes
If your opponent sent garbage in the first bag, there is a 10% of chance that the hole will appear below where you would place the I piece, ruining, thus, the continuation of your normal route. There are three cases to consider here (we will refer to possible garbage sent by players in TETR.IO): 1-block hole (double, single combo), 2-block hole (triple, T-Spin Single), 4-block hole (TSD, Quad). Below, we show some examples of how to deal with all these situations. The rule of thumb is to place the I-piece in the same place as you would do in the normal route and, if possible, right before you place the T-piece so that it counts as a Combo (which compensates for the Back-to-Back bonus lost by placing the I-piece).
- 1-block hole: It breaks the b2b bonus, but it performs a TST anyway. After that, one can follow up with a 6-3 stacking.
1-block hole |
1-block hole |
1-block hole |
1-block hole |
6-3 (L>S) |
6-3 (S>L) |
- 2-block hole: It breaks the b2b bonus, sends one line of garbage (two lines cleared), and performs a TSD. After that, one can follow up with a b2b TST tower (the first two setups will cover 96.67% of all your bags).
2-block hole |
2-block hole |
2-block hole |
2-block hole |
TST tower (T>S) |
TST tower (L>T) |
TST tower (S>T) |
- 4-block hole: It preserves the b2b bonus while performing a Quad. If possible, try to hold the T-piece until you place an I-piece in the next bag to perform a TST afterwards. If you can't do it (because the T-piece in the next bag comes early), place it there and perform a Tetris clear. After that, you can follow up with a 2-7 stacking.
4-block hole |
4-block hole |
4-block hole |
4-block hole (Hold T or... |
place it for Quad. |
Variant route gone wrong (S>I)
|
|
|
|
|
Third Bag
Normal route
The second bag can always be stacked like this if there is no hole (due to the garbage sent from your opponent) in the first column from the left (if a hole appears at that point, see the 'Garbage routes' below). If possible, you should always try to place the S-piece before the J-piece, as this will avoid dealing with the garbage problem and soft dropping at the same time. One may need to wait for gravity if the O piece comes earlier than the J or S piece and later than the Z piece. Placing the L-piece can take some time if the O-piece arrives first.
|
|
|
|
|
|
|
|
|
Garbage routes
Although there would be three cases to consider here (like in the previous bag) when a hole spawns right below where you would place the J-piece, there can be essentially two ways to deal with all of them together and leave a 'clean' board, as shown below:
- J>Z: This preserves the b2b bonus.
J>Z |
J>Z |
J>Z |
J>Z |
- Z>J: This breaks the b2b bonus but leaves a cleaner board.
Z>J |
Z>J |
Z>J |
Z>J |
It's important to notice that the I-piece does not play a critical role in building a T-spin setup (one can always perform a T-Spin Single when Z>J), so it can be used as a counterspike if the hole is 4-block height (there is a 40% of chance that other blocks do not cover the hole, before placing your third bag).
Freestyle routes
- 6-3 stacking: The first two setups below will cover 93.33% of all your bags, so you will likely switch to a clean 6-3 stacking without wasting any T-piece. In the worst case, you need to delay the TSD.
6-3 stacking |
L>S |
S,O>L or S>L, O>J |
S>L (not clean board) |
Delayed |
- Center-4-wide
|
|
|
|
Fourth Bag
At this point, one has two options to perform a TSD and aim for a high PC chance in the fifth bag. During this phase, there is also an extra setup in case you want to ensure b2b preservation (at the cost of losing any chance for a PC).
TSD setups
- Setup-1: This setup requires: 1) L before Z, or 2) O before Z and L before I (cover rate → 70%). It preserves the b2b bonus, and the PC success rate following this setup is 89.72%. As we will see below, if one fails to perform a PC in the fifth bag (because of queue pattern or garbage on the board), then one can always build a setup for a TST or a Tetris clear.
|
|
|
|
|
|
|
|
- Setup-2: This setup requires Z before L (cover rate → 66.67%). It breaks the b2b bonus, but the PC success rate following this setup is very high, being 99.44%. On top of that, there is a very good chance to perform a Tetris clear to complete the PC. The cover rate of building either Setup-1 or Setup-2 is 100%.
|
|
|
|
|
- Setup-3 (b2b preservation): This setup (alternative option to Setup-2) requires Z before L (cover rate → 66.67%). Performing PC after this setup is impossible, but it preserves the b2b bonus if one has garbage on their board. The cover rate of building either Setup-1 or Setup-3 is 100%, and both preserve the b2b bonus. The residual at the end of the bag can be different depending on whether the O-piece arrives before the J-piece or vice versa. This won't change the setup of the 5th bag so much.
O>J |
Base |
Base |
O>J |
O>J |
J>O |
Base |
Base |
J>O |
J>O |
- More TSD setups: There are actually many more TSD setups than the three shown above, and one of them can even lead to a 100% PC chance, but their dependencies are unrelated to the Z and L-piece. So, we preferred to keep it simple and minimise the number of setups one should learn at this stage. To see the other setups, see here [1].
Fifth Bag
Setup-1 route
- 14L PC route: As mentioned above, there is an 89.72% PC chance if one took the Setup-1 route in the previous bag. This PC has 15 minimal solutions (see all of them here [2]). Below, we show three main solves (the cover rate of all these combined is 68.33%):
50% (SITOLZJ) |
33.3% (TISOZJL) |
32.5% (TZSOJIL) |
- TST route (greedy players-risky route): If you can't achieve PC because your queue can't solve it or there is garbage on your board, you can always build a TST setup and freestyle from there. This is a risky route since it may leave your board not so clean, although there are TSD follow-ups after it.
TST route |
Base |
O>J |
S>J>O |
J>O>S (worst case) |
- Quad route (downstacking-safe route): If you have too much garbage on your board and want to stay safe, then downstacking is a wiser choice. You can perform a Tetris clear and leave your board very clean afterwards.
Quad route (T>Z) |
S>L, T>Z |
L>S, J>O, T>Z |
O>L, J>S, T>Z |
Quad route (S>T) |
Z>J, S>T |
J>O, L>Z, S>T |
The previous setups will leave your board ready for a TSD follow-up (on the left side of the board) and cover 83.57% of all your bags. You can still build a setup for the remaining bags that will leave your board clean after the Tetris clear (see here for other setups [3]), but you need to improvise afterwards.
Setup-2 route
- 14L PC route: There is a 99.4% PC chance if one took the Setup-2 route in the previous bag. This PC has 36 minimal solutions (see all of them here [4]), which sounds a lot but one can learn 4 main solves, and the success rate of performing a PC would decrease by only 2.6% (or, equivalently, the PC success rate becomes 96.79%). As shown below, 3 of these solutions will be completed with a Tetris clear (overall, there is a 54.72% PC chance with a Tetris clear):
60.6% (ILZOSTJ) |
37.0% (LTOSZJI) |
34.4% (JSOTLZI) |
30.9% (JSOZTLI) |
- TST route (greedy players-risky route): Like in the Setup-1 route, you can build a TST setup if you can't achieve a PC chance, although the success rate of building it is 80%, and it leaves the board not clean (you will most likely lose the b2b bonus after this bag). More specifically, it requires that the Z-piece comes earlier than the I, O, or J-piece (the base pieces are, like in the Setup-1 TST route, the S, Z and L-piece).
TST route |
Base |
Z>J |
Z>O |
Z>I |
The previous setups and the four solutions for the PC shown above will cover 99.76% of all your bags (for 100% success, you need to learn the 21st solution you see among the 36 ones in the previous link).
- Quad route (downstacking-safe route): Here, again, if you have too much garbage on your board and want to stay safe, then downstack with a Tetris clear, leaving your board very clean afterwards. There are many ways to do so (see here [5] for all possible setups ), but there is one single setup that can be built with 100% success rate, as shown below:
Quad route |
S,Z>O |
S>O>Z |
O>S,Z |
Z>O>S |
The T-piece will be used as the overhang for a TSD follow-up.
Setup-3 route (b2b preservation)
- O>J in 4th bag: If you get the O-piece earlier than the J-piece in the 4th bag (when Z>L), then the continuations shown below will cover all your bags. If you also get O>J in this bag (it happens 2 out of 3 times), you can perform a TST. Alternatively, you can always build your stack to perform a TSD, which can be followed up with another TSD in the 6th bag.
O>J in 4th bag |
Base |
O>J |
L,I>J>O |
I>J>L>O |
J>I,L,O |
- J>O in 4th bag: If you get the O-piece later than the J-piece in the 4th bag (when Z>L), then the continuations shown below will cover 95% of all your bags. If you get O>J in this bag (it happens 2 out of 3 times), you can perform a TST. Alternatively, you can build your stack to perform a TSD, which can be followed up with another TSD in the 6th bag.
J>O in 4th bag |
Base |
O>J |
L>J>O |
I>J>L,O |
J>I>L>O |
To reach full coverage, one can build one of the two setups shown below, although the board won't be clean, and one needs to improvise after that.
J>O |
J>I,O |
Alternatively, if one gets an early J (J>O), then a wiser choice would be downstacking with a Tetris clear, if possible, with one of the setups shown below (the cover rate is 98.61% with the four main setups shown earlier):
O>S>T |
S>Z>T |
S>T>Z, O>Z |
O>ZT , TJ>S |
Z>J>ST, O>T |