[eaglesfan371]

Say you have a model that describes a league of teams by rating with significant degree of confidence and can predict match probability.

Say you have team A with a rating of 4.0
Say you have team B with a rating of 3.9

Team A @ team B, in a league where home factor is worth 0.2

Thus, it would imply the rating would be:

Team A 4.0 vs Team B 4.1 (3.9 + 0.2 home)

Thus team B should be slightly favored.



However, team A has won the past 10 matchups vs team B including several this season. Team A is favored over team B while the model states this should not be. The public will likely hammer Team A.


Assuming no injuries, how do we determine a correlation between past results of specific matchups to incorporate in a rating or is this mathmatically not recommended, as this would be recency bias and this value is already in the individual team rating?

I would argue specific matchups will be correlated in some ways. Some will have a correlation near 0 while others seem to have trends. From a macro perspective the overall rankings per team using a model explain the value of the team vs another random team on a neutral venue but on a micro scale, vs specific teams, a smaller correlation should apply.

Thoughts on how to determine this? Do linesmakers ever put up bad lines knowing when the public will be all over them and refuse to move those lines even when sharps max bet it?

[vampire assassin]

Try running your default model. Let P be the odds you project for a home team to win. Calculate your RMS for all the matches you have. For each match, this is (1-P)^2 if the home team one, and P^2 if the home team lost. Your average RMS is the sum

Now change your model's weighting. Give the last 10 matches a weighting of 0.5 to 1, and matches older than that (this season a weighting of 0.5. Does that meaningfully improve your RMS? You might try different weightings, (like a weighting of 0 to 1 for the whole season) and see what works best.

[gojetsgomoxies]

i would love to see an academic study showing whether recent performance is under or over incorporated into lines.

stock market for years was under-incorporated. but alot of difference between sports betting and quant momentum investing. one big thing with stocks was that historically many giant equity investors were slow moving/acting.

i saw nate silver suggesting there is too much recency in NBA lines. i think that was what he said.

[KiDBaZkiT]

Do linesmakers ever put up bad lines knowing when the public will be all over them and refuse to move those lines even when sharps max bet it?

You wrote all that Sherlock Holmes $#!+ and then had to ask this question? Why you should take your degree and never gamble again. Couple years from now you will wish you took my advice. It is not a book-smart guys game. Never will be. Always been for those with street smarts always will be.

[Gaze73]

"Team A @ team B, in a league where home factor is worth 0.2"

That's too simplistic. Each team has individual home/away factors, some teams just can't play worth a damn on the road but are super tough at home.

[semibluff]

Say you have a model that describes a league of teams by rating with significant degree of confidence and can predict match probability.

Say you have team A with a rating of 4.0
Say you have team B with a rating of 3.9

Team A @ team B, in a league where home factor is worth 0.2

Thus, it would imply the rating would be:

Team A 4.0 vs Team B 4.1 (3.9 + 0.2 home)

Thus team B should be slightly favored.



However, team A has won the past 10 matchups vs team B including several this season. Team A is favored over team B while the model states this should not be. The public will likely hammer Team A.


Assuming no injuries, how do we determine a correlation between past results of specific matchups to incorporate in a rating or is this mathmatically not recommended, as this would be recency bias and this value is already in the individual team rating?

I would argue specific matchups will be correlated in some ways. Some will have a correlation near 0 while others seem to have trends. From a macro perspective the overall rankings per team using a model explain the value of the team vs another random team on a neutral venue but on a micro scale, vs specific teams, a smaller correlation should apply.

Thoughts on how to determine this? Do linesmakers ever put up bad lines knowing when the public will be all over them and refuse to move those lines even when sharps max bet it?

The 1st part: Previous results aren't necessarily a factor and thus they don't definitely, positively, absolutely, 100% have to be included in the predictive model. What is important is being aware that competitors may view a match-up differently dependant on other factors. It is impossible to formulate and quantify those factors to any predictive model so you have to add them manually. For example when the Steelers play the Ravens there are years of divisional rivalry behind the game that won't necessarily show-up in a model that predicts the outright result. What a model might do is pick up on a lower scoring trend or a tendency for games to be closer than predicted...or not, (because i'm not going to look it up). Either way as a bettor you need to be aware that the mental approach to the game and the playcalling will be different. You have to adjust your predictive model as you see fit. A more complicated example would be a Premier League game between Spurs and West Ham. It's a much bigger game for West Ham fans than it is for Spurs fans and players can be influenced by that. Playing the game mid-week under floodlights also changes the atmosphere. Another factor can be what's at stake. If the Spurs @ West Ham game is late in the season and has nothing on the line then it could well be a tepid affair with a lot of developmental players getting game time. If Spurs are chasing the title and West Ham are comfortably safe then you might expect West Ham to be uninterested and defensively soft. This would be completely wrong. West Ham would be hugely motivated to deny Spurs a title. It would be their best physical effort of the season - even though it gets them nothing. Models can't predict this.

The last part: Books are there to make money. The safest way to make money long-term is by positioning their odds to manipulate the money market into equal liabilities on either side of a line. Books are NOT there to predict sporting outcomes. They predict those outcomes as a guide to the betting lines but those lines are subject to what the book believes the total value of the betting market is and how much money will go on either side at particular prices. However, trying to guess the market position rather than taking a view on the actual outcome can dramatically shrink the market. If it's a small market then books will effectively ignore which side money is going - other than as a guide to whether they have the line wrong. If it's a huge market such as an NFL game then books are much more interested in which side they believe money is going and odds will reflect this. If the public see an event as a 55.5% to 44.4% outcome but the think-tank behind the book sees it 50% either way then the book will choose to be nearer -125, +125, (excluding juice), rather than -100, +100. Whether the line ever hits either position or stays somewhere in between depends on where the money goes. Books make errors predicting outcomes and they also misjudge which side gambling money will fall.

...so yes. Books regularly post lines that don't 100% reflect their thoughts on an outcome, but the lines aren't normally a long way off.

[danshan11]

books can also try and be deceptive with lines to avoid a sharp knowing he is sharp, it is a common tactic and discussed often on pinnacles podcast. they say its a trick to keep sharps at bay. if they consistently see lines moving their way they are more likely to increase their bets. this is not a daily every time occurrence but they do use it

say pinnacle thinks a line is sharp on side A they will purposely create more space for sharps to cover a heavy position pinnacle has on side B, even though they think the sharp side is A

[Gaze73]

books can also try and be deceptive with lines to avoid a sharp knowing he is sharp, it is a common tactic and discussed often on pinnacles podcast. they say its a trick to keep sharps at bay. if they consistently see lines moving their way they are more likely to increase their bets. this is not a daily every time occurrence but they do use it
say pinnacle thinks a line is sharp on side A they will purposely create more space for sharps to cover a heavy position pinnacle has on side B, even though they think the sharp side is A

That's stupid for 2 reasons: If you're a sharp winning at least 10 out of 12 months, you don't care about their tricks, you have proof you're sharp and you know why your picks have good value. And if Pinnacle says they post deceptive lines then every sharp listening to that podcast or reading this thread knows about their tricks which makes them ineffective. In some games I am 100% sure the line is deceptive and I don't give a hoot if the price moves up or down.

[danshan11]

Gaze your opinion is valid but I doubt you know what a sharp actually is.
A sharp in general someone who over all has a slight edge in the long term over tons and tons of bets.

[flipacoin9698]

Run your equations until you go mad... that is not the approach to find winners.

Cap the market not the game

[Gaze73]

Run your equations until you go mad... that is not the approach to find winners.

Cap the market not the game

Exactly! The market does all the homework and we just find the errors. I rarely ever look at form.

[danshan11]

the primary way to know if the market is wrong is to create a fair line for the side and total. how can you determine if a bet is a good bet if you dont create a line?

[tsty]

Exactly! The market does all the homework and we just find the errors. I rarely ever look at form.

Lol thats not what he meant

You are so far off its retarded

[gojetsgomoxies]

there have been many famous cases where there was good betting volume on lines that were clearly wrong.. i'm thinking though that alot of them had a tourist collectors item element (tiger woods to win all 4 majors in a year, or the triple crown winner in horse racing where lots of people didn't cash their winning ticket) OR you couldn't take the other side. so not game bets per se.

[Gaze73]

Lol thats not what he meant

You are so far off its retarded

What did he mean then smartass? He literally said equations are not the way to find winners and I fully agree. Just think outside the box.

[danshan11]

Gaze vs tsty now this could get interesting. I am staying out just so I can laugh at these two mastermind bettors waging betting brain war.