Stacking/Downstacking

When playing Tetris, you are either stacking or downstacking at some point; this article will try to explain how to do both efficiently. Stacking and downstacking can also be synonymous with being offensive and defensive.
==What are they, and when to use them?==
When stacking, you are placing down many pieces (in a uniform fashion) without clearing garbage so that when you do clear lines, you clear many at a time. Note that you may stack for T-spins or Tetrises, but this article will only be geared towards Tetrises.
When downstacking, you are trying to keep your field as low as possible, while clearing many singles/doubles to make your field even lower. Note that it is only feasible to clear singles/doubles when downstacking.
So when should you stack or downstack? When playing aggressive players you will have to change gears and switch between the two quickly. Here are a few tips to decide when to do the following:
- Create a "threshold" for yourself; you can put yourself into stacking mode when you are above a threshold defined by you (for example, if your stack is over 12 blocks high), and downstack when your stack is under the threshold. Read the following situations to get a better idea of what to do.
- Your stack is above the threshold and higher than your opponent's: Downstack.
- Your stack is below the threshold and lower than your opponent's: Stack.
- Your stack is below the threshold and higher than your opponent's: In this case, either answer is acceptable, though you might need to get more situational. Look at what your opponent is preparing for you. If he has a clean stack with a Tetris ready to go, then you want to downstack.
- Your stack is above the threshold and lower than your opponent's: This is the scenario that separates good players from the not-so-good players. In this case, your opponent will always be downstacking, so the amount of garbage he is going to send to you will be minimal. When possible, you should be going for the kill in this case. Decide how many more lines you need to send and build a double/triple/Tetris to finish your opponent.
==How to stack efficiently ==
:Main article: Upstacking
This article by Ryan Heise provides sage advice for stacking. The idea is to go for a clean stack so that you can Tetris quickly using as few pieces as possible. When stacking well, you should be able to get any piece and have a place for it on your field. There are two ways to send Tetrises - quick and consistent, or set up many potential back-to-back (b2b) Tetrises. It is usually better to go with the former if you are the faster player, and to go with the latter if you are slower. Slower players can beat faster players only if they have good spiking potential. (Two b2b Tetrises would make a decent spike if the opponent isnt ready to block)
Look at the following examples; assume you are below the threshold.
Example 1 - Turning garbage into Tetrises
Example 2 - Deciding to make a second Tetris for more spiking potential
Example 3 - Tetris opener by Caffeine with SZO start
Example 4 - Basic Tetris opener by L-mino
Example 5 - B2B Tetris opener by ManofMiracles
==How to downstack efficiently ==
:Main article: Downstacking
When downstacking, the major rule is to not place a piece that would cover a hole in the near future. Try looking at the next 1-3 holes, and avoid piece placements over those holes. With Flat Stacking, you can throw away pieces that you don't need while keeping your stack low. However, you should drop fewer than 4 pieces per line you clear. Here is a good example of downstacking.
An even better method of downstacking would be combo downstacking; by clearing a line(s) on each piece, you can be offensive and defensive at the same time!
Contrary to what was previously said, it is okay to cover a hole if you can clear it quickly. See some examples below.
Example 1
==Practice problems==
coming soon
Category:General Methods