T-SPINS · LESSON 6 OF 6
When the T doesn’t come
A wait has a price: one safe landing for every piece before T. Count that price, keep a reserve when you can, and abandon the slot before its roof traps you.
Two draws left means at most one non-T first.
Suppose you know the bag boundary and have drawn I, O, J, L, S. Only Z and T remain. T is one of the next two draws; at most one other piece comes first. Find Z a safe landing and you have a concrete reason to preserve the slot.
“T has not appeared yet” alone gives no two-piece guarantee. If only one piece of this bag has been drawn, six remain. Across bag boundaries, T can be first in one bag and last in the next, leaving as many as 12 non-T draws between Ts.
Every seven-bag contains T; there is no T-free bag. A short visible stretch can lack T, and Hold can reorder placements. Count generator draws separately from pieces locked on the board.
A T in Hold is LST’s reserve. Store it while no slot is ready; spend it when a safe Double is ready. If T is neither visible nor held, leave the roof open unless a known bag and safe intervening placements justify the commitment.
Choose while more than one landing is still safe.
- Wait
- T is held, visible, or bounded by a tracked bag. Give each intervening piece a supported landing outside the reserved entry. If one piece has nowhere to go, the plan is incomplete.
- Extend
- An existing TSD base and the visible pieces support the Fractal construction from lesson four. You have room to store height while waiting for two Ts. Do not turn an unknown wait into an automatic extension.
- Bail out
- The next piece would seal the entry or create an unrelated hole, or waiting would push the board too high. Fill the planned slot with a usable piece or take a small clear while that route is still open.
Turn the planned TSD into a normal Single.
This is the decision just before the J roof from lesson two. T is absent from NEXT and Hold. Instead of spending J on the right bank to make a roof, place it lower across the intended arm space. It clears a row without a T-spin and leaves the well open.
The dashed cells were reserved for T. J can still enter from above.
Its top cell sits at 6. Its three-cell base completes the upper row.
One J cell remains above the stack. The channel at 7 is open and no buried cell was added.
This is an early exit, not a claim that J fits every already-roofed T slot. After a roof is closed, check the rotation or slide route again. In the mirror, L does the equivalent job. A Single can break B2B, but it is preferable to committing to an unreachable setup.
A skim can reopen the board.
A small clear can lower the stack and preserve access to a well instead of waiting for a larger attack.
If a small clear removes a restriction, compare the space it opens with the cost of preserving the old slot. The skim above illustrates removing a row; the J sequence shows the piece placement that makes one. Neither choice needs to preserve the original spin plan.
Play twenty LST Doubles and tally each T wait.
- Start a fresh LST game and aim for 20 on the TSD counter. Keep a spare T in Hold when you have no ready slot.
- Whenever you reserve a slot without a held T, note T’s position in NEXT. Count each new non-T drawn before T arrives; a swap with an occupied Hold does not draw from the bag.
- For each wait, record the count and your choice: preserve, extend or bail. A held or immediately available T has a wait of zero.
- Bail out before the next piece seals the entry. A normal repair clear is allowed in this drill; continue towards twenty Doubles once the board is playable again.
Use the TSD counter for the target and a small tally for waiting draws. This is a decision drill, not the strict zero-accidental-hole run from lesson two.
Open LST practice ↗Gravity Off · NEXT 5 · Auto Play off. The link selects the mode; set these practice options yourself.
Common mistakes
Mistaking recent locks for a known bag
Hold can bring back a piece from an earlier bag. Use a tracked draw boundary or the actual preview, not a guessed seven-piece window.
Saving T after its slot is ready
The reserve is there to complete a good clear. Hoarding it while the stack rises defeats its purpose.
Only considering bail-out after the roof is sealed
The J exit is available because the entry is still open. Make the choice before spending that access.
Bag bound: TetrisWiki: Random Generator. The J bailout and wait-tally drill are original teaching examples.