Twitter Question – Using Opening Lines/Totals Instead Of Closing Lines/Totals, How Much Variance Would We See In The Results For NCAAF and The NFL?
We got a question via Twitter from @SkatingTripods, a friend of our site from @BTBFourm, who asked how much variance we would see for football ATS results if the outcomes were calculated using Opening Lines instead of the Closing Lines.
Just a quick FYI, @SkatingTripods and @lindetrain, AKA Adam Burke and Matt Lindeman, host a weekly podcast focusing on sports handicapping. The discussion is never about 100 Star Locks of the Week and instead offers intelligent debate and useful information. They have two shows under their belt as of this writing and I think they have done great job, so if you get a chance, please check them out.
Some miscellaneous notes and observations:
- The data is presented for the Previous 2011/2012 Season as well as All History, which represents all data going back to the 2007/2008 season
- Analysis is presented for NCAAF and the NFL by ATS and Total
- For both ATS and Totals we have calculated what would have been the outcomes using the Opening Line/Totals and compared that against the actual data
- Specific to ATS, there is a somewhat confusing situation that occurs when the Favorite Flipped from the Opening Line to the Closing Line. In this scenario for example, what was an Opening Home Favorite would be a Closing Home Dog. So for some of the line items you will see Closing Result Favorite/Open Result Dog – NO CHANGE
- In my initial exchange with @SkatingTripodsI told him my off the cuff guess is that there would be minor variance in NCAAF and the NFL a bit more, but still not too significant. The finding were interesting to me in that more games were affected than I would have anticipated.
- For NCAAF ATS All History showed that 4.5%, and for the Previous Season 5.2%, of the games would have changed
- For NCAAF Totals All History showed that 4.4%, and for the Previous Season 2.8%, of the games would have changed
- For NFL ATS All History showed that 4.4%, and for the Previous Season 5.2%, of the games would have changed
- For NFL Totals All History showed that 5.2%, and for the Previous Season 5.6%, of the games would have changed
- It is important to note that for the percentages differences listed above, it does not necessarily mean that you would go have gone from a loser to a winner or a winner to a loser. In many cases a Push comes into play where you either had a Push based on the Closing number and an outcome based on the Opening number, or an outcome based on the Closing number and a Push based on the Opening number. The percentage differences simply indicate that there was some sort of change between the two calculations.
- The right most column in the spreadsheets indicates the percentage difference from the Previous Season as compared to All History for each line item.
In the embedded Excel workbook below, you will find the following worksheets:
- NCAAF_ATS–COMPARATIVE LOOK AT ATS RESULT DIFFERENCE FOR OPEN INSTEAD OF CLOSING NUMBERS
- NCAAF_ATS–COMPARATIVE LOOK AT TOTAL RESULT DIFFERENCE FOR OPEN INSTEAD OF CLOSING NUMBERS
- NFL_ATS–COMPARATIVE LOOK AT ATS RESULT DIFFERENCE FOR OPEN INSTEAD OF CLOSING NUMBERS
- NFL_TOTAL–COMPARATIVE LOOK AT TOTAL RESULT DIFFERENCE FOR OPEN INSTEAD OF CLOSING NUMBERS
On the Excel Web App toolbar of embedded spreadsheet, if you click the right-most button, View Full Size Workbook, the entire workbook will open for viewing in a new window
We hope you find the information an asset to your handicapping and please visit our free site, GreyMatterStats, where we put this information at your fingertips.
If you find something of interest that you would like to share, please feel free to leave a comment or Tweet us @GreyMatterStats