Tuesday, January 29, 2013

How Not To Handicap A Prop Bet (2013 Edition)

Second annual!

For the most part, you don't see things with lots of obvious factual errors or inconsistencies posted on major online publications. This is because editors exist. However, an exception to this rule can be made for topics relating to sports betting. There's really no reason to think an editor would know anything about math, let alone gambling.

On this topic, the editors probably assume that the writer knows more than they do, and just focus on spelling, punctuation, sentence structure, etc. Especially if the writer previously wrote for a stats-focused football website, and lived in Vegas during the 2011 NFL season, the editor assumes that the writer must have at least a basic grasp on simple concepts relating to math and betting.

Boy, are they mistaken. Take it away, Bill Barnwell:
Will there be overtime?
Yes: +700
No: -1000

Vegas normally gives the team at home an average of three points on the spread, so if the 49ers were at home, we'd expect this line to be 49ers -6.5; if they were in Baltimore, the line would be 49ers -0.5.
This makes no sense. I honestly don't understand how this isn't ridiculously obvious to anyone who thinks about it for more than two seconds. For the eight millionth time: ALL POINTS IN THE NFL ARE NOT OF EQUAL VALUE. Teams win by three a bit more often than they win by five. You can't just blindly add or subtract three from the spread.

This becomes especially clear when Barnwell claims that the spread would be 49ers -0.5 in Baltimore. So, if HFA was worth four points, that spread would be 49ers +0.5 which is...the exact same thing (in the playoffs). But we made HFA worth 33% more, how did it not change? It's lazy and wrong to calculate it this way.
Bet on a specific margin of victory.
Ravens win by 1-4 points: +450
49ers win by 1-4 points: +350

If you really thought the game was going to be close, you could bet $100 on either side of this line and basically get +300 odds that the game was going to finish with one team winning by three points or fewer, since you'd win $250 if the Niners prevailed by 1-4 points (the $350 prescribed in the odds above minus $100 for a losing bet on the Ravens winning by 1-4 points) and $350 if the Ravens won by 1-4 points.
So, by betting $100 on either side, we are risking a total of $200, to win either $250 or $350. And we are claiming this is the equivalent to getting +300? Huh? What just happened?

Also, I'm pretty sure "1-4 points" and "three points or fewer" are not the same thing.
Total number of different 49ers to score
Over 3.5: -130
Under 3.5: +110

A defensive or special teams touchdown would make this one really likely to succeed, so you could parlay the +165 odds on that occurring with the Over 3.5 odds here if you wanted.
This is similar to last year's Gronkowski example, where Barnwell says one simple thing that immediately makes it clear he doesn't understand anything.

Parlaying these two is a great idea, except for one small problem, which is clearly stated on the LVH odds sheet that Barnwell links to:
Of course you can't parlay these. If you could, it would basically be printing money, since lots of them are very correlated. If you could, it would be ridiculous to only mention it in one throwaway line of a post, because it would be such a profitable strategy that it would render every other aspect of props-related analysis completely irrelevant. But:
Moving on.
Will there be a safety?
Yes: +900
No: -1300

This was my biggest prop bet loss last year. I laid out the logic suggesting that betting "No" was a good play, followed through with a bet, and managed to lose within seven minutes of the opening whistle. It was such a big loss that I needed to win every other one of my prop bets to break even (and that didn't happen, either).
Just wanted to cut in real quick and mention that this is my favorite part of this whole train wreck. But sorry, continue educating us, Bill.
But here, again, I'm going to point out why the "No" bet is the right one. Over the past five years, there have been 1,280 NFL regular-season games and 82 safeties, suggesting that safeties will occur in 6.4 percent of games. The odds above suggest, after adjusting for the vig, that safeties will occur in 9.7 percent of games. Furthermore, the most likely scenario that leads to a safety — a quarterback getting sacked in the end zone — is unlikely to occur, since these two teams have had relatively anemic pass rushes during the playoffs. So, again, I think there's value in betting "No" here.
What the fuck is this?

The price that gets you to a breakeven of 9.7% is -931. So, yeah, "no safety" would be a good bet at -931. The thing is, and this should really be clear to anyone that can read, the odds on "no" are not -931. They are -1300. So, the 9.7% is completely irrelevant when you're deciding whether or not to bet. The number we should be using is 7.1%, which is really not that close to 9.7% at all; in fact, it's quite close to 6.4%!

I really hope there's a safety.
How will the opening coin toss land?
Heads: -102
Tails: -102

This is basically a sobriety/IQ test from Vegas to see if you're interested in giving them free money. The LVH actually moved the vig on this up from one cent (-101/-101) a year ago to two cents this year, suggesting that they think they can get just as much action on this bet with the extra juice.
Not much to see here, just your basic absence of logic. The vig is twice as high now, of course they don't need to get the same amount of action for this to be a good idea.
How long will Colin Kaepernick's first rushing attempt go?
Over 5.5 yards: -110
Under 5.5 yards: -110

If Kaepernick doesn't have a rushing attempt, the Under bet wins. If his first run is a kneel-down at the end of the first or second halves, the Under bet wins. The median run for Kaepernick this year is four yards, but the mode (most frequent) run for Kaepernick across his 81 carries is for seven yards.
The mode is completely irrelevant. Why are you bringing it up as a counter-argument against the lower median? It just doesn't matter at all, and offers no value beyond what the median gives you. Not that the median is even the best way to analyze this (the concept of looking at "distributions" seems to be generally lost on Bill). How do you possibly have a job where math is one of the core competencies?
Which color will the Gatorade/liquid dumped on the winning head coach be?
Clear/water: +175
Orange: +250
Yellow: +250
Green: +750
Red: +750
Blue: +750

Red just seems like such a great long shot when you consider that one of the teams wears red as its primary color. Finding purple Gatorade to soak John Harbaugh might be a little more difficult.
I realize most people don't/shouldn't take handicapping these silly prop bets as seriously as I do, but this is completely just making shit up. Since when do people choose the flavor of Gatorade they drink based on their team's colors? Why would they do that? It doesn't even make any sense.
How many times will the game be referred to as Harbaugh Bowl, Har Bowl, or Super Baugh during the game?
Over 2.5: -110
Under 2.5 -110

Someone is going to get paid by an online sportsbook during the game to watch the contest and just listen for whether the announcers refer to it by any of the above names. What a wonderful, dumb world we live in. This seems low to me, even if the Harbaugh family isn't in attendance; one video package might be enough to knock this one out.
Rules? What rules?
From kick off until final whistle. Live pictures only, any taped pictures or past video does not count towards wager. Half time does not count towards wager. Must say full name. Book manager's decision is final.
Good work, Bill.

1 comment:

  1. "Since when do people choose the flavor of Gatorade they drink based on their team's colors?"

    Not sure about what they actually drink, but I noticed that Alabama was partial to pouring red on Saban. I would guess that only a handful of teams (mostly college) consider the color they pour as it relates to their team colors.

    Of course, some coaches (including Saban) have let it be known that they prefer water over Gatorade.