21 point teaser EV question

[EricW]

This is kind of a probability question but it relates to NFL betting so I'll post it here:

My friend is thinking of doing a 10 team, 21 point teaser for the NFL. He has to risk $170 to win $100. He has to go 10/10 to win, but he gets 21 points for each game.

What is the EV for this and how would one calculate it?

[DougOzzzz]

Using data from NFL games from 93 to 04, I get 94.837% of the games that a team managed to cover the spread +21 points. I'm not sure how ties effect this bet, but I will ignore them for now.

Anyway, the probability of winning this is simply .94837^10 or about 58.85%. That's not enough to make it profitable (needs ~63%) but it's not impossible that if your friend picks the correct 10 sides that it could be +EV.

Frankly I'm a little surprised because when I read this I thought it would be a much bigger "suckers" bet.

Edit: What are the rules on ties? This could have a pretty significant effect, and if "ties lose" is the case, the win pct drops to 55.3%.

[craig r]

My guess is that ties lose. The OP said you had to win them all. Of course, they could just mean that you can't lose even one.

craig

[Action Scott]

Doug, Where do you get those stats, i'm kind of new to sports betting. Thanks.

[tech]

Can you include totals too, or just sides?

Anyone know what site takes this bet? If it is not appropriate to say feel free to pm me.

[kdog]

5Dimes takes these things. They call them Monster Teasers and ties lose.

Tech...you can use totals in them too,even team totals. I was looking at them the week Baltimore played Pittsburgh and the over for the Ravens for a 14 pt teaser was 4 /images/graemlins/smile.gif

[plus_man]

5dimes does take this kind of bet but not at those odds.

[plus_man]

I'd also like to know what site your using for this.

[tech]

[ QUOTE ]
5Dimes takes these things. They call them Monster Teasers and ties lose.

Tech...you can use totals in them too,even team totals. I was looking at them the week Baltimore played Pittsburgh and the over for the Ravens for a 14 pt teaser was 4


[/ QUOTE ]

Yeah but there is no way they can do it at those odds, at least I don't think. I haven't done the math on this, but here is my gut feeling. If I have to make 10 selections on sides teasing 21 points each at -170, I'm not sure that is +EV. If I can include sides and totals, I'm pretty sure it would be +EV. If I can include sides, totals, and team totals, the place will be broke in a month. /images/graemlins/grin.gif

[plus_man]

[ QUOTE ]
I was looking at them the week Baltimore played Pittsburgh and the over for the Ravens for a 14 pt teaser was 4

[/ QUOTE ]

Are you sure this wasnt Baltimores total after teasing it? /images/graemlins/confused.gif

[plus_man]

Im sorry. I misread.

[DougOzzzz]

I seriously doubt they include totals. I checked, and teasing the over with 21 points hits at 95.61% (counting ties as losses). That's enough to make it +EV to blindly tease all overs. Remove the highest 3rd of the totals, and you're up to 96.34% and a teaser win-rate of about 69%.

[ohnonotthat]

I don't have time to read all the responese - likely someone else answered correctly but just in case . . .

A teaser is a parlay of 2 [or more] events; these events range in likelyhood of occurrence from ~ 68% (6 point line move) to upwards of 90% in the case of this 21 point line move.

In order for this wager to be +EV, the [average] chance of each individual selection winning must be > 95.5%.

I'll leave it to someone else to explain how one arrives at this exact figure.

- Also, the use of the word "average" is not technically correct but the precise explanation would be extremely complex (translation: I might very possibly botch it /images/graemlins/frown.gif)

*

A 6 point teaser must feature two selections that each have an expected success rate greater than the square root of .5 (50%) to be +EV since this bet pays even money.

The sq. root of .5 is ~ .7071 (sq root of 50% is 70.71%)

Did this help ?

[ohnonotthat]

several sites that offer this wager.

WWTS used to, and still may.

5dimes offers teasers from +6 to +21 and everything in between. (5, 5.56, 6.5, 7, . . . 9.5, 10 10.5 . . . 14, 15, 16, 17 . . . 21).

The payoffs at 5dimes are about as good as any you'll find on the 'net.

I don't play teasers so it's a moot point for me but if you do this is a good place to do so.

They also have reverse teasers (aka "pleasers") where you GIVE 6, 6.5 or 7 points and get an inflated payoff rather than a reduced one.

There the outcome of any event is less than 100% you'll find a line on it here.

Division III football ?

- Uh huh

HIGH SCHOOL FOOTBALL ?

- Uh huh

*

And they pay !

[ohnonotthat]

Do ties lose ?

Never noticed that before.

Better stick to the half-point games /images/graemlins/smile.gif

[ohnonotthat]

Totals are allowed; team totals are not.

I am checking as we speak to make certain this has not changed but it has been this way for years.

[ohnonotthat]

All their other teasers use the "ties count as no action and the teaser reverts to a one-fewer-selection bet" - it's not likely they'd have one rule for 6 point teasers and a different one for 20 pointers.

I have been looking into this further. 5 dimes offers monster teasers up to 20 points. A ten team teaser lays odds of -250. In the NFL you can tease sides, totals, and team totals. In the same bet you can also tease 1st half totals and 1st half sides.

Its a little late now but you can also use the 20 points on college totals and sides but not team totals. Do it in the same bet as NFL games.

Interesting numbers for this week you could bet-
Chicago o2
chicago/pitt o5.5 for the first half
texas +27

[DougOzzzz]

[ QUOTE ]

Interesting numbers for this week you could bet-
Chicago o2
chicago/pitt o5.5 for the first half


[/ QUOTE ]
yeah, these are interesting.
[ QUOTE ]

texas +27

[/ QUOTE ]
This doesn't seem so interesting to me.

[tech]

Just for the hell of it, I decided to see exactly what 5dimes would let you do in these. It took me forever to place the bet because they won't let you do a lot of correlations and such. /images/graemlins/frown.gif But if you are interested, here is what I ended up with. I had to lay -225 on this. I didn't really want the Indy/Jax o22, but by the time I realized it was in there I did not want to go back through the whole thing again.

Disclaimer: I'm not suggesting this is a +EV bet -- this was just for kicks and to test their correlations check.

Dec-11 1:05 PM TAMPA BAY Individual Total Over o5½
Dec-11 1:05 PM NEW ENGLAND/BUFFALO Over o14.5
Dec-11 1:05 PM CHICAGO +27
Dec-11 1:05 PM CHICAGO/PITTSBURGH Over o10
Dec-11 1:05 PM INDIANAPOLIS +10½
Dec-11 1:05 PM INDIANAPOLIS/JACKSONVILLE Over o22
Dec-11 4:10 PM NY GIANTS +10
Dec-11 4:10 PM NY GIANTS/PHILADELPHIA Over o16½
Dec-11 4:20 PM MIAMI Individual Total Over o5½
Dec-11 4:20 PM DENVER +4½
Dec-11 4:20 PM KANSAS CITY +23

[kdog]

[ QUOTE ]
All their other teasers use the "ties count as no action and the teaser reverts to a one-fewer-selection bet" - it's not likely they'd have one rule for 6 point teasers and a different one for 20 pointers

[/ QUOTE ]

Check the rules for monster teasers. All the way at the bottom it says "ALL TIES LOSE"

[ohnonotthat]

I did - and they do.

I'm filing this under "oops".

- Chris