BASKETBALL ON PAPER 1 Math & Basketball: Astronomy used to be just watching pretty stars, too Dean Oliver Author, Basketball on Paper Consultant to the Seattle Supersonics Using Sports to Teach Math Symposium Seattle, WA May 13, 2006
BASKETBALL ON PAPER Dean Oliver 2 Some History Every science we have today was once just “interesting” Chemistry Biology Astronomy Finance and economics Physics Interesting + math = science Math = Science - Interesting
BASKETBALL ON PAPER Dean Oliver 3 Language and logic first… Score a game
BASKETBALL ON PAPER Dean Oliver 4 …Then counting… How many lines? How many lines with a score? How many touches? How many post-ups? How many offensive rebounds off missed free throws?
BASKETBALL ON PAPER Dean Oliver 5 …And Analysis Same number of possessions… Equivalence scale on possessions Per available rebound Basketball on Paper Points per possession Four Factors Effective shooting percentage Turnovers per possession Offensive rebounding percentage Free throw rate
BASKETBALL ON PAPER Dean Oliver 6 Stories to tell Grades Is ___ the next Michael Jordan? Who should we draft? Is __ a good coach? Tactics Why so many offensive rebounds? Is offense better when forcing more touches? Should we double team the post? Is it easier to shoot an open jump shot from 3pt range or a contested one from 2pt range? Financial Should a team pay more to win? When do players get their big paycheck?
BASKETBALL ON PAPER Dean Oliver 7 The Possession Framework Possessions are equal What you do per possession is what matters Possession ends: Missed shot rebounded by defense Made field goal, no free throw Turnover Made last free throw Possession formula: (FGA – FGM – OR) + FGM + TOV + 0.4*FTA
BASKETBALL ON PAPER Dean Oliver 8 Floor% and Play% Floor%: Percentage of possessions on which there is a score Scoring Possessions/Possessions Play%: Percentage of “plays” on which there is a score Scoring Possessions/Plays
BASKETBALL ON PAPER Dean Oliver 9 Four Factors Effective Field Goal Percentage (FGM * FG3M)/FGA Turnover Percentage TOV/Poss Offensive Rebounding Percentage OR/(OR + OppDR) Free Throw Ratio FTM/FGA
BASKETBALL ON PAPER Dean Oliver 10 Test! Seattle 1998 eFG%: 52.1% FT%: 72% TOV%: 15.7% LA Lakers 1998 eFG%: 51.9% FT%: 68% TOV%: 16.2% Better offense?
BASKETBALL ON PAPER Dean Oliver 11 Answers Lakers had better offense pts/100 poss to How? Shot worse from everywhere Rebounded worse Turned ball over more But… Shot 600 more free throws! More shots of overall higher percentage shot
BASKETBALL ON PAPER Dean Oliver 12 More Framework: Estimating Wins Wins come from point difference (points/possession) Wins ~ A*(points – points allowed) B*(pts/poss – pts allowed/poss) points C /(points C + points allowed C )
BASKETBALL ON PAPER Dean Oliver 13 Changes in tempo/rules have impact…
BASKETBALL ON PAPER Dean Oliver 14 Wins from a Bell Curve
BASKETBALL ON PAPER Dean Oliver 15 Bell Curve Principles Consistency matters Playing up or down to opponent matters Don’t blow teams out by too much Unbiased referees change odds
BASKETBALL ON PAPER Dean Oliver 16 Player Evaluation What makes a good player? Almost the same as what makes a good team Roles/Interactions affect everything Volume of shots Communication Coordination
BASKETBALL ON PAPER Dean Oliver 17 Decreasing Marginal Returns
BASKETBALL ON PAPER Dean Oliver 18 Optimize Lakers’ Offense Unbalanced offense More balanced offense
BASKETBALL ON PAPER Dean Oliver 19 Overall Player Ratings “Ratings” aren’t objective What are you measuring? Offense, defense, (in)tangibles
BASKETBALL ON PAPER Dean Oliver 20 Other Projects Best player to step up to help offense What to emphasize on defense How will players develop? How to help them? What tactics to take against good teams? What tendencies do teams have to take advantage of? How to predict player performance from another league?
BASKETBALL ON PAPER Dean Oliver 21 Work with 82games.com They do research projects Ahead by 3, foul or defend? Does Steve Nash help his teammates? What does Kobe Bryant do in the clutch? How likely is it to make a shot after making the previous one?