Metric
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Revision as of 09:57, 18 February 2012 by Kenneth (talk | contribs) (→Summary of different metrics)
A metric (more specifically, move count metric or turn metric) is a convention for measuring move count. The same sequence of moves can have different move counts depending on the metric used.
Summary of different metrics
For more details, see the respective articles.
- HTM; Half Turn Metric (or Face Turn Metric): Any face turn of any angle counts as 1 turn.
- QTM; Quarter Turn Metric: Only quarter (90-degree) face turns count as 1 turn.
- STM; Slice Turn Metric: Any turn of any layer, by any angle, counts as 1 turn.
- ATM; Axial Turn Metric: Any movement within the same axis counts as 1 turn.
- ETM; Execution Turn Metric: Any perceived movement counts as 1 turn.
- BTM; Block Turn Metric: A metric for measuring movecounts on Bigcubes
Uses
HTM has been used to. For example, God's number is known to be 20 in HTM. From a mathematical standpoint, however, QTM seems a more natural choice; half-turns are visibly redundant as generators.
Debate over metric in FMC
WCA uses HTM in FMC. There has been a number of debates arguing for different metrics.
