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Equation 18 · Part 1 · A Showdown Ladder Rating Measures the Ladder, Not the Player

Symbol R

RR
RR

What this part means

R is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

Its job in the formula

R is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

The passage around this formula

…3 ] . Line up the two constructions and the correspondence is not loose: RR. ​ Rating deviation RD\mathrm{RD} , bounded to Showdown’s 25–130 range 95% interval: X ±\pm 1.96 ⋅\cdot SEM\mathrm{SEM} 95% interval: R ±\pm 2 ⋅\cdot RD\mathrm{RD} [ 3 ] Reliability rises with more independent items RD falls with more games played in a period [ 2 ] Reliability falls with time since calibration RD rises with time since the player’s last game [ 3 ] This is the article’s original contribution: not the observation that a…

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