If moving to the Ross K. Smith 100-point scale increases the accuracy of speaker points, and if speaker points accurately reflect a team's abilities, we might expect that the scale change would help speaker points predict future winners. To my surprise, there is not a dramatic increase in the predictive accuracy of speaker points in the three large tournaments that moved to the new scale while maintaining the same number of teams and preliminary rounds.

I used the following model: Predictions are made for rounds five and later, using at least the first four preliminary rounds. The model makes no prediction if the two teams have different win-loss records. If they have the same win-loss record and the same total points, the model also does not make a prediction. Otherwise, it predicts that whichever team had the higher points for the predicting rounds will win the debate.

If two teams have the same record for rounds one through four, but they don't meet until round eight, the model still predicts the winner based on their points in rounds one through four, since the teams might well have debated in round five. It also makes predictions based on their points in rounds one through five, one through six, and one through seven, assuming their win-loss records are the same after rounds five, six, and seven. All predictions are based on rounds one through four, five, six, or seven; no predictions ever discard any early prelims.

#### Wake Forest, 8 prelims

Year | Teams | Tied points, no prediction | Correct prediction | Incorrect prediction | Accuracy |
---|---|---|---|---|---|

2006-2007 | 138 | 11 | 89 | 50 | 63.0% |

2007-2008 | 134 | 1 | 101 | 79 | 56.1% |

#### UNLV open division, 7 prelims

Year | Teams | Tied points, no prediction | Correct prediction | Incorrect prediction | Accuracy |
---|---|---|---|---|---|

2008-2009 | 56 | 0 | 32 | 23 | 58.2% |

2009-2010 | 54 | 0 | 20 | 11 | 64.5% |

#### Harvard, 8 prelims

Year | Teams | Tied points, no prediction | Correct prediction | Incorrect prediction | Accuracy |
---|---|---|---|---|---|

2008-2009 | 80 | 9 | 57 | 27 | 66.1% |

2009-2010 | 87 | 4 | 68 | 33 | 66.7% |