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Point spread

As explained in Statistics Slam Dunk

A point spread is a betting handicap expressed as a difference in expected scores between two opposing teams.

A point spread is a betting handicap expressed as the expected-score difference between opposing teams. In analysis, compare opening and closing spreads with the final scoring margin. section 17.4.3 section 17.5.2

Evaluating opening versus closing spreads

Across 1,230 games, the closing spread was closer to the final margin 493 times, compared with 553 games favoring the opening spread; 184 were equal. Mean absolute error was 9.92 for closing spreads versus 10.1 for opening spreads, so the closing spread outperformed by approximately 2%. 

oddsdf4 %>%
 mutate(spreadmove = case_when(abs(closespreadH) > 
                               abs(openspreadH) ~ "up",
                               abs(closespreadH) < 
                               abs(openspreadH) ~ "down",
                               abs(closespreadH) == 
                               abs(openspreadH) ~ "same")) -> oddsdf4

oddsdf4$spreadmove <- factor(oddsdf4$spreadmove)

Inspect the R transformation that converts spread movement into an analyzable factor. section 17.4.3

How Statistics Slam Dunk covers it

How deep it goes
Develops derived errors, movement categories, grouped comparisons, and averages, stopping short of predictive modeling.
Examples
Uses 1,230 NBA games, opening and closing spreads, final margins, movement categories, monthly totals, and SmartEDA reports.
What it assumes
Assumes game-level points and spread fields while defining margins, spread errors, and movement categories through executable transformations.
What you can do after
Evaluate opening and closing spread accuracy with dplyr, tidyr, and SmartEDA summaries and visual diagnostics.
How it connects
Connects point spreads with final scoring margins, exploratory data analysis, categorical variables, and data wrangling.
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Related concepts

This explainer was generated by Manning's knowledge graph from the text of Statistics Slam Dunk. The section links point to the parts of the book it draws on.