Friday, October 31, 2014

Turnover Index - Week 9

Here are the Turnover Index picks (of which there are none) for Week 9. The Turnover Index is a simple betting strategy based on the theory that the market overvalues defensive turnovers when judging team strength. See here and here for more background.

Week 8 results

No games satisfy our betting criteria this week, but here are updated results from Week 8.

Our two Week 8 picks went 1-1 against the spread. The Saints covered against the Packers quite easily. The Jets, however, did not (despite cunning attempts at subterfuge). Although we went 1-1, we actually had a positive ROI this week (one dollar!) because our Kelly Criterion-based betting rule placed slightly more of our bankroll on the Saints than on the Jets. Here are the season to date results:
  • Against the Spread: 3-1-0
  • Starting Bankroll: $1,000
  • Current Bankroll: $1,048 (5% ROI)
Here is the week by week performance:

amount betprofitsending
7 2 2 $1,000 $51 (5.2%) $47 $1,047
8 2 1 $1,047 $26 (2.6%) $1 $1,048

The "Old" Index

Under the original, simpler betting approach (bet any game with at least a 10 defensive turnover differential between the teams), season to date results for 2014 are 2-0 against the spread.

Wednesday, October 29, 2014

Week Nine Playoff Implications now available

Week nine playoff implications, complete with interactive charts, are now available at FiveThirtyEight. There are a lot of high leverage games this week, including Thursday Night's Panthers-Saints matchup and Sunday's Ravens-Steelers game. In this week's write-up, we delve into the intricacies of playoff seeding, most notably the race for the top AFC seed and how Sunday Night's Brady-Manning duel will shape that contest.

Tuesday, October 28, 2014

The NBA Returns

Note: It appears I have jumped the gun with my original post. My play by play data source drastically altered its formatting over the offseason, wrecking all of my code. So, NBA Win Probability graphs for the 2014-15 season will be on hold until I am ready to roll out my planned enhancements (which will be based on a different data source). The original, incorrect, version of this post is below.

The 2014-15 NBA season kicks off tonight, and with it, so will my win probability features:

I also have been working on several key enhancements to these features. I had hoped to have them ready by the time the season opened, but I ran out of time. However, I hope to roll them out soon. In the meantime, the existing tools will be available and updated daily(ish) until I am ready for the big rollout.

Wednesday, October 22, 2014

Week Eight Playoff Implications now up at FiveThirtyEight

Week eight playoff implications, complete with interactive charts, are now available at FiveThirtyEight. Cincinnati is on the hot seat this week, with 27% playoff probability at stake in their game against the Ravens. In the NFC, pretty much everybody will be hoping for the Panthers to upset the Seahawks (aside from the Saints, Falcons, and Buccaneers).

Turnover Index - Week 8

Here are the Turnover Index picks for Week 8. The Turnover Index is a simple betting strategy based on the theory that the market overvalues defensive turnovers when judging team strength. See here and here for more background.

Week 7 results

Our betting strategy got off to a good start, going 2-0 against the spread. The Patriots, despite forcing 14 turnovers in their first six games, were not able to manage a single one against the Jets. They won the game, but failed to cover the 9.5 point spread. On Monday Night, the Texans saw first hand how random the turnover battle can be, conceding two quick touchdowns to the Steelers off of turnovers deep in their territory (see how their win probability went into freefall).

Here are the results. We are up $47 off of our starting $1,000 bankroll.
  • Against the Spread: 2-0
  • Starting Bankroll: $1,000
  • Current Bankroll: $1,047 (4.7% ROI)

Thursday, October 16, 2014

Playoff Implications moving to FiveThirtyEight

I'm excited to announce that my Playoff Implications feature is moving to FiveThirtyEight. Here is a link to the week seven column. Data visualization genius Reuben Fischer-Baum has created a slick and intuitive interactive chart for displaying the various probabilities. Under the hood, I have increased the number of simulations from 10,000 to 50,000. As a result, some of the more minor implications are now passing statistical muster, leading to a fuller picture of playoff interdependencies.

The intention is to run this as a weekly column at FiveThirtyEight. Each week, I'll post a heads up here when the column is up.

Turnover Index - Week 7

Finally, a chance to lose some money. Week seven marks the first official appearance of the Turnover Index. The Turnover Index is a simple betting strategy based on the theory that the market overvalues defensive turnovers when judging team strength. See here and here for more background.

Driving the lack of betting opportunities is a lack of turnovers in general. Turnovers in the NFL have been declining for well over twenty years now. Through week six, teams have averaged just 1.5 turnovers per game, the lowest level going back to 1989. See chart below:

Wednesday, October 8, 2014

Playoff Implications - Week 6

Here is your week 6 guide to playoff implications. The purpose of this feature is to highlight games that have a significant impact on the playoff picture (see this post for background).

The playoff implications below are derived from the same simulation I run to calculate playoff seed probabilities for my daily NFL rankings. I can group the simulation runs by the outcome of each game and then see how a team's playoff chances vary between the two groups. The interactive table at the bottom of the post will allow you to see corresponding results for any game or team.

Ranking Week 6 Games by Leverage

The table below ranks the week 6 games by total leverage. Leverage in this context is a measure of both how uncertain a game's outcome is (games between evenly matched teams have higher leverage) and how much the playoff picture swings as a result of that outcome.

Saturday, October 4, 2014

Turnover Index - Week 5

Turnover 001Just a heads up that I plan on continuing the Turnover Index for the 2014 season. But there are no games that satisfy our betting criteria this week. Check back next week.

NFL Week 4 Power Ranking Roundup

Cam Newton 2014Last year the Carolina Panthers, after starting the season 1-2, led the NFL in win percentage from weeks five through sixteen, winning 10 of their next 12. Who saw that coming? Prior to their 10-2 run, ESPN had the Panthers at #21 in their weekly power rankings. My own betting market rankings had them ranked 18th. Football Outsiders' DVOA was closer to the mark, ranking the Panthers 6th. What's known as the Simple Ranking System was even closer though, ranking the Panthers 3rd.

When it comes to prediction, we are quick to forget how wrong we often are. So, in a post from earlier this year, I compiled early season NFL power rankings from multiple sources over multiple years and attempted to objectively measure how good each ranking system is at predicting wins (i.e. a more comprehensive version of the Panthers example above).

I intend to do the same comparison for 2014, so I figured I would go ahead and archive the week 4 rankings in this post, and then check back on them when the season has finished. Note that when I say "week 4 rankings", they are rankings compiled after week 4 of the season has been completed (and prior to Thursday night's Packers-Vikings blowout). Here are the ranking systems I'm comparing: