Early Season NBA Over/Under Bias

Main Article Content

Clay Girdner
Justin Davis
Andy Fodor
David Kirch

Abstract

In this paper we analyze the total line betting market for National Basketball Association (NBA) regular season games for the 2009-2012 seasons.  Specifically, we divide seasons by week and analyze points scored, total lines and game statistics such as field goal percentage and turnovers.  We find the NBA total line market is generally very efficient with points scored and total lines increasing nearly evenly over the first 17 weeks of the season before leveling off.  However, the total line market is inefficient in Week 1 with 58.2% of first week games having total scores less than total lines during our sample period.   This win rate is significantly higher than the 52.38% win rate required for profiting from the betting strategy.  Betting under total lines on all games in the first week on the 2009-2012 NBA season yields average returns of 11.1% per game.

Article Details

Section
Articles

References

E. Baryla, R. Borghesi, W. H. Dare and S. Dennis ‘Learning, price formation and the early season bias in

the NBA‘ (2007) 4 Finance Research Letters 155-164. http://www.sciencedirect.com/science/article/pii/S1544612307000177

M. DiFillippo, K. Krieger, J. Davis and A. Fodor ‘Early season NFL over/under bias’ (2013) Journal of

Sports Economics forthcoming. http://jse.sagepub.com/content/early/2012/06/22/1527002512454544.abstract

O. A. Entine and D. S. Small ‘The role of rest in the NBA home-court advantage’ (2008) 4 Journal of

Quantitative Analysis in Sports 1-9. http://www.degruyter.com/view/j/jqas.2008.4.2/jqas.2008.4.2.1106/jqas.2008.4.2.1106.xml

E. F. Fama ‘Market efficiency, long-term returns, and behavioral finance’ (1998) 49 Journal of Financial

Economics 283-306. http://www.sciencedirect.com/science/article/pii/S0304405X98000269

E. F. Fama ‘Efficient capital markets: II’ (2012) 46 The Journal of Finance 1575-1617.

http://onlinelibrary.wiley.com/doi/10.1111/j.1540-6261.1991.tb04636.x/abstract

J. M. Gander, R. A. Zuber, T. O’Brien and B. Russo ‘Testing Rationality in the point spread betting

market’ (1988) 43 Journal of Finance 995-1008.

http://onlinelibrary.wiley.com/doi/10.1111/j.1540-6261.1988.tb02617.x/abstract

J. M. Gander, R. A. Zuber and W. H. ‘The search for informed traders in the totals betting market for

national basketball association games’ (2000) 1 Journal of Sports Economic 177-186. http://jse.sagepub.com/content/1/2/177.short

J. M. Gandar, R. A. Zuber and R. P. Lamb ‘The home field advantage revisited: a search for the bias in

other sports betting markets’ (2001) 53 Journal of Economics and Business 439-453. http://ideas.repec.org/a/eee/jebusi/v53y2001i4p439-453.html

P. K. Gray and S. F. Gray ‘Testing market efficiency: Evidence from the NFL sports betting market’

(1997) 52 Journal of Finance 1725-1737. http://ideas.repec.org/a/bla/jfinan/v52y1997i4p1725-37.html

R. J. Paul and A. P. Weinbach ‘Bettor misperceptions in the NBA – the overbetting of large favorites and

the hot hand’ (2005) 6 Journal of Sports Economics 390-400. http://www.cabdirect.org/abstracts/20053196241.html;jsessionid=9002BD7D927AA64D3EA49DC5E98AD215?gitCommit=4.13.20-5-ga6ad01a

R. J. Paul and A. P. Weinbach and M. Wilson ‘Efficient markets, fair bets and profitability in NBA totals

-96 to 2001-02’ (2004) 624-6332 The Quarterly Review of Economics and Finance 624-632. http://www.sciencedirect.com/science/article/pii/S1062976903000334

R. D. Sauer ‘The economics of wagering markets’ (1998) 36 Journal of Economic Literature 2021-2064.

http://www.jstor.org/discover/10.2307/2565046?uid=3739600&uid=2&uid=4&uid=3739256&sid=21101900816757