魔方怎样才算转一步（QTM、FTM、ATM、STM、ETM、LTM）

weekend

怎麼樣稱做将模仿转「一步」呢？一般習慣上只要一個面有轉動，不管轉了多少，就算「一步」，轉90度、轉180度都算一步，這種計步方式英文稱作「Face turn metric(FTM)，也叫Half Turn metric（HTM）」。另一種計步方式，是只要轉90度就算一步，因此轉180度時，就要算兩步，英文稱作「Quarter turn metric(QTM)」

国内一般都用FTM。

R，L，U，D，F，B，R'，L'，U'，D'，F'，B'，r，l，u，d，f，b，r‘，l’，u‘，d’，f‘，b’ 在FTM算法算1步，在QTM也算1步
R2，L2，U2，D2，F2，B2，R2'，L2'，U2'，D2'，F2'，B2'，r2，l2，u2，d2，f2，b2，r2‘，l2’，u2‘，d2’，f2‘，b2’ 在FTM算法算1步，在QTM算2步

M，相当于x'RL'，在FTM算法算2步，在QTM也算2步
M'，相当于xR'L，在FTM算法算2步，在QTM算法也算2步
M2，相当于x'2R2L'2，在FTM算法算2步，在QTM算法算4步
M'2，相当于x2R'2L2，在FTM算法算2步，在QTM算法算4步

E，相当于y'UD'，在FTM算法算2步，在QTM也算2步
E'，相当于yU'D，在FTM算法算2步，在QTM也算2步
E2，相当于y2'U2D2'，在FTM算法算2步，在QTM算法算4步
E'2，相当于y2U2'D2，在FTM算法算2步，在QTM算法算4步

S，相当于zF'B，在FTM算法算2步，在QTM也算2步
S'，相当于z'FB'，在FTM算法算2步，在QTM也算2步
S2，相当于z2F2'B2，在FTM算法算2步，在QTM算法算4步
S'2，相当于z2'F2B2'，在FTM算法算2步，在QTM算法算4步

还有
BTM: Block Turn Metric ,a metric for bigcubes where any group of contiguous slices moving the same way is counted as one move.

half turn metric (HTM), also known as the Face Turn Metric (FTM)，不管哪一个面转90度或180度，都算一步。

LTM: Layer Turn Metric ，就是STM

STM: The slice turn metric (STM) is a metric for the 3x3x3 where any turn of any layer, by any angle, counts as one turn. This differs from HTM in that a slice move counts as one turn, not two. And it differs from the ATM in that it does not include anti-slice turns and other axial turns. 这种算法，不管哪一层转90度或180度，都算1步
Cube rotations do not count as turns. STM is a very popular metric for those who use methods with many slice turns (such as Roux) although the official Fewest Moves event uses HTM.
The following algorithm would count as 10 turns STM: r2 U R' U' M U R U' R' r' (an edge 3-cycle on the front face).

ATM: The axial turn metric (ATM) is a metric for the 3x3x3 where any movement within the same axis counts as a single move. This includes quarter turns, half turns, slice turns, and antislice turns，这种算法r, R, M, LR, LR'都算一步。

ETM:The execution turn metric,is a metric for the 3x3x3 where any perceived movement counts as a turn; this includes rotations. Therefore, the interpretation of this metric can be somewhat subjective. For example, U2 can be either 1 or 2 moves. ETM was designed for measuring 'true' TPS by David Woner. It is intended mainly for reconstructions, where videos are available to see how many movements were actually performed，这种计步方法，魔方整体转动也要计算步数，x，x2算一步还是2步，不同的人有不同的算法。

范例：
Scramble: L2 R2 U2 L2 U F2 L2 F2 U L B2 F' R B2 U' B F L F2 D'

Cross: L2 u R' F' (4 ETM, obvious)
F2L 1: L' U' L d R' U R (7 ETM, obvious)
F2L 2: y' R U' R' U2 R U' R' (8 ETM, rotation requires regrip so it is counted)


F2L 3+4: y L U2 L' R U R' (7 ETM, rotation counts, L' R counts as two moves not one, because it is performed as such)
OLL: M U' M' U' U' M U' M' (8 ETM, Slice moves are performed as slices here. The U2 is two flicks with the left index, thus two moves.
PLL: R' U2 R U' U' R' F R U R' U' R' F' R2 U' (15 ETM, the first U2 is an index-middle double flick with the right hand, thus one move. The second is two left indexes again, thus two. R2 is a single wrist turn, thus one.)
Total solve: 56 QTM/49 FTM/49/HTM/44 STM/49 ETM

[ 本帖最后由 weekend 于 2011-10-9 21:15 编辑 ]

weekend

就是在别的网站看到这些缩写别糊涂而已。