The randomizer appears to be history of length 3. Until some hidden condition is met (5 Bravos?), it will only pick from pieces not in history, so any 4 consecutive pieces dealt are all different until that point.
Case notation: +X-Y means X held, Y missing from next piece preview.
| Case #
|
Missing
|
| I
|
L
|
O
|
T
|
J
|
| Held
|
I |
1 |
2 |
3 |
4 |
2
|
| L |
5 |
1 |
6 |
7 |
8
|
| O |
3 |
6 |
1 |
9 |
6
|
| T |
10 |
11 |
12 |
1 |
11
|
| Z |
5 |
8 |
6 |
7 |
1
|
Case 1: One of each piece
Can be mirrored.
//TODO: Permutations that don't work with this build or its mirror image.
Case 2: +I-L, +I-J
Diagram for +I-L, mirror for +I-J.
//TODO: Permutations
Case 3: +I-O, +O-I
Use held I or O first. Make a 4x2 with I's or O's. (Note: For +O-I in 20G, build the 4x2 on the right to ensure the second O can reach its destination.) With remaining L, J, T, clear depending on their relative order:
TLJ: (hold J until after second O/I if necessary)
TJL: Symmetrical to TLJ.
LTJ or JLT: Hold T, reduces to above cases.
LJT:
Case 4: +I-T
Use held I first, then hold the second I if necessary. Build depending on relative order of L, O, and J, then finish with I for a Tetris Bravo:
| OLJ, OJL |
LOJ, JOL |
JLO, LJO
|
|
|
|
|
Case 5: +L-I, +J-I
Strategy for +L-I, mirror for +J-I.
Build depending on relative order of L, O, and J:
OJL, OLJ, LOJ: Use held L first, then hold the second L if necessary.
JOL: Same as above. Hold J and use the held L, then hold the second L and use the held J. Alternate no-hold strategy:
LJO, JLO: Hold J
Case 6: +L-O, +J-O, +O-L, +O-J
(Note: For +O-* in 20G, build the 4x2 on the right to ensure the second O can reach its destination.)
Diagram for +L-O, mirror for +J-O. Hold J if necessary.
Diagram for +O-L, mirror for +O-J. Hold L if necessary.
Case 7: +L-T, +J-T
Diagram for +L-T, mirror for +J-T.
//TODO
Case 8: +L-J, +J-L
Diagram for +L-J, mirror for +J-L.
//TODO: Permutations
Case 9: +O-T
(Note: In 20G, build the 4x2 on the right to ensure the second O can reach its destination.)
Mirror only the left two columns if J comes before L, since O's spawn in columns 3 and 4.
Hold L or J (whichever comes second) if necessary.
Case 10: +T-I
//TODO
Case 11: +T-L, +T-J
Diagram for +T-L, mirror for +T-J.
If I comes first, hold J for Triple Bravo:
Otherwise, use held T first, hold I:
The above will not work in 20G for TIOJ or TIJO, in which case save the held T for last and use the following alternate builds:
Case 12: +T-O
//TODO
