Tetris The Absolute The Grand Master 2

Tetris The Absolute The Grand Master 2 is the second arcade game in Arika's TGM series. Among other things, TGM2 introduced the less-intimidating Normal Mode to attract more casual gamers, as well as an all-new grading system in Master Mode, the continuation of TGM's original gameplay. Shortly after TGM2 was released, Arika offered a free upgrade to a PLUS version, which added TGM+ Mode and the famous T.A. Death Mode.

Normal
Normal mode behaves behaves similarly to Master Mode in gravity and speed timings, but stops at level 300. At levels 100 and 200 an item block is given to the player. "Free Fall," which eliminates all holes, is given at 100. "Del Even," which clears every other row throughout the field is given at 200. The credit roll challenge is a slow 20g, but playing through it is not required for a "Clear". For this mode, the player's score is multiplied by six.

Speed Timings
The unit for gravity is G (rows per frame), as a fraction with a constant denominator of 256. This means G = Internal Gravity/256. For example, at levels 90 through 99, the gravity is 64/256G, or 1/4G.

Master
Master mode is Arika's upgrade to the original Tetris The Grand Master gameplay. One of two very important differences is that the speeds continue to increase throughout the 500–999 levels. The other difference is the all-new grading system. The grading mechanism now exists completely independently from score, and rewards efficient and consistent play throughout (for example, it's extremely difficult to attain S9 before level 900).

Other changes include a hard drop that doesn't lock, which improves sub-20g play by allowing Zangi-moves. The Grand Master qualifications were also greatly expanded, and includes an invisible challenge during the credit roll where pieces disappear immediately after being locked; topping out results in rank M. Arika is currently hosting a video showing a Gm performance: tgm2master.

Grade Recognition System
Each time lines are cleared, a hidden parameter ("Internal Grade Points") will increase. When this parameter reaches 100 or more, it will reset to zero and another hidden parameter ("Internal Grade") will increment by one. The table below shows the correspondence between "Internal Grade" and the actual Grade displayed on the screen. To encourage faster and more efficient play, the "Internal Grade Points" will continually drain away, potentially back to zero, for every frame of gameplay that the player has control of a tetromino and doesn't have a combo going. The decay rate is dependent on the player's current "Internal Grade" and is shown on the table below in units of frames per point.

The number of "Internal Grade Points" awarded is dependent on 4 other variables:
 * Number of lines cleared: a 4-line clear is generally worth more than a 3-line clear and so on.
 * "Internal Grade": a higher "Internal Grade" generally means less points.
 * The line clear's position in a combo. Note that tetrises are an exception to this. They will score the same number of "Internal Grade Points" regardless of their position in a combo. Just like the CO medal, clearing 2 or more rows will increase the combo, while singles will merely maintain the current position.
 * The player's Level after the line clear.

The following formula determines the "Internal Grade Points" awarded by a particular line clear. The "ceil" indicates that when the Combo Multiplier is applied to the Basic Amount, the game rounds the multiplication up.

Awarded Grade Points = ceil(Basic Amount x Combo Multiplier) x Level Multiplier

The Basic Amount is determined by the player's current "Internal Grade". Also shown is the decay rate mentioned above. For example, internal grades 20 through 22 could be thought of as S4-, S4, and S4+, but TA does not display these differently.

Depending on the number of rows cleared and the current size of the combo, a different combo multiplier is applied to the grade points.

Finally, depending on the level, one of four level multipliers is applied to the awarded grade points. This equals 1 + floor(level / 250), or equivalently a value from the following lookup table:

Eg. At level 555, Grade 1, clearing 2 doubles in a combo, the first and second doubles respectively will be worth: ceil(12 x 1.0) x (1 + floor(555 / 250)) = 12 x 3 = 36, ceil(12 x 1.4) x (1 + floor(558 / 250)) = 17 x 3 = 51

This is a complicated system that may be difficult to understand, but it ultimately measures how efficiently and consistently the player can stack and make non-singles in steadily increasing speeds. Further interesting observations about the grading system are as follows:


 * Immediately following a grade increase, the grade points are at 0. There is therefore nothing to lose from building the stack higher, until you clear a line.
 * From level 750-999, a tetris will always increase the internal grade.
 * The level multiplier is significant. When you enter section 700 and the music changes, it is a good idea to stack the screen high in order to clear more lines after level 750. Combined with the previous observation, 2 tetrises will get you 2 "Internal Grades" instead of only 1, doubling your rate of progress.
 * Combos aside, even though 2 singles are worth much less than a double, and 4 triples are less than 3 tetrises, 3 doubles are actually worth more than 2 triples.

The M-Roll
In order to achieve the M and Gm Grades, certain conditions must be met in order to activate a special credit roll at level 999 (often called the "M-Roll") where the tetrominoes become invisible as soon as they are locked. The conditions for the "M-Roll" differ significantly from the PLUS version, and are currently believed to include at least the following:

The M Grade is awarded as soon as the "M-Roll" begins (as opposed to TAP, where the M Grade is only awarded upon topping out), and survival results in the Gm Grade.

Doubles
Doubles is a two player cooperative mode that puts both players in one well that is 14 units wide instead of 10. It is accessed by entering a special code, though it was made selectable from the menu in TAP.

Each player has a separate level counter, and both players must reach level 300 for the win. Though the level counter does not stop at every x99 as in standard modes, the final 299 does require a line change to 300. If one player reaches 300 before the other, he enters 20g for the rest of the game. It is quite difficult to survive for long with 20g in such a wide well, so winning requires a fine degree of coordination between the players so that they reach 300 synchronously.

Versus
The versus mode in TA works in a very similar way to that in its predecessor, TGM. Each player has their own field, and clearing two or more lines in their field will cause garbage lines to be sent to the bottom of their opponent's field. Unlike the multiplayer modes in other Tetris games, the garbage holes correspond to the location of the line clearing piece. This means that the usual playing style of the series, of leaving a column down the right for Tetrises is not as beneficial, because if both players do it then any garbage sent will line up with the opponent's Tetris hole. Alternating sides, or using other pieces to clear lines will send garbage that is more difficult to the opponent to clear. Oddly enough, the versus mode in Bloxeed' and Dreamworld's DuelTris worked in a similar manner.

All of the four single player modes can be played in Versus mode. The first player picks a mode, and starts as if playing alone. When the second player pushes their respective start button (assuming there is a credit) they will be asked if they want to challenge the other player. If they choose 'yes', then the other player will lose their game, "Here comes a new challenger" will scroll across the screen, and versus mode will start in whatever mode the first player was playing in. Normal, Master and Death use their respective speed curves for each player. TGM+ mode has garbage rising automatically from the bottom, in the same way it does on single-player. To prevent unwanted versus games, the first player can press their start button, which will cause "no more challenger" to display on the opposite field. Pressing the start button again cancels this effect. If a second player starts while "No more challenger" is displayed, then it will skip the challenge menu and go straight to the mode select.

For versus there is a default target level of 200, and a default time limit of 2:40:00. The target level can be changed in the game setup (in 100 level increments), with the time increasing or decreasing by 1:20:00 for every 100 levels. If a player tops out their field, then they lose. If neither player tops out their field in the allocated time limit, then the winner is the player with the highest level. If a player reaches the target level then the game ends and they are declared the winner. By default, the overall winner is the first player to win two games. Again, this can be changed in the game setup.

Items
Each player has a green bar to the side of their field. With each piece placement, this bar increases slightly. When the bar is filled, the next piece the player receives will be an item piece. The shape of the piece is retained, but the appearance of the individual composite blocks will be different, depending on the item. The piece is placed normally, and the item is used automatically when a line containing part of the item piece is cleared. Again, Bloxeed was the inspiration here. Many of the powerups, like the 16 ton weight, and the delete even, are based around the ones in Bloxeed. But unlike in Bloxeed, DuelTris, and Tetris DS, the entire piece counts as the item, instead of just one block of it.

Items can be turned off by each player holding their respective start buttons as Versus mode is initiated.

Scoring
Unlike the first game in the series, score is completely unimportant in Master Mode's grading system. The algorithm is identical to TGM1, with an extra bonus added for sonic drops. The equation is:

Score = ((Level + Lines)/4 + Soft + (2 x Sonic)) x Lines x Combo x Bravo

Where:
 * Level is the current level you are on.
 * Lines is the number of lines you just cleared.
 * (Level + Lines)/4 is rounded up.
 * Soft is the cummulative number frames during which Down was held during the piece's active time. Note that this means manually locking pieces already on the ground will increase the Soft value by 1.
 * Sonic is the size of the single greatest sonic drop during the piece's active time. Note that this is non-cummulative.
 * If the previous piece cleared no lines, Combo is reset to 1. Otherwise and its Combo value is:
 * Combo = (previous Combo value) + (2 x Lines) - 2
 * Example: A double-triple-single combo will have combo values 3, 7, and 7 respectively.
 * Bravo is equal to 4 if this piece has cleared the screen, and otherwise is 1.

It should be noted that Normal mode multiplies line clear scores by 6. Also, the player is given a time bonus of 1253 x Seconds where Seconds is the amount of time in seconds, rounded up, that the clear time is below 5 minutes.