Greening up YouTube

[ForFolksSake]

You want to be making as many +ev (positive expected value) trades as possible and limiting the number of -ev trades to a minimum.

Assuming that greening up trades are likely to be -ev, you're probably better off keeping greening trades to a minimum. Therefore you might want to close the original trade using slightly different stake in order to create a green result across the card without having to green-all afterwards, so creating less overall trades.

eg; backing £10 @ 2.02 then laying £10 @ 1.98 would require a further green-all command in order to green up across all runners after a successful trade.
But if you back £10 @ 2.02 then lay £10.20 @ 1.98, this creates a +£0.20 green result across all selections without needing to green all afterwards.

So what 'Betfair' odds are used to 'plot' a P/V chart e.g

Actual trades, presumably?

... and a bet/trade can be +/-ev for any 'price' matched between 1.01 and 1000

[ShaunWhite]

... and a bet/trade can be +/-ev for any 'price' matched between 1.01 and 1000

Yes.
EV is a measure of the difference between the price you get and the likelihood of the event happening.
Think of it as the average amount you'll win or lose.

Eg heads in a coin toss.
1.9 = -EV
2.1 = +EV
3.5 = even more +EV.

EV per £1 staked = (Price × True_Probability) - 1


Where:
True_Probability = your estimated chance of winning (as a decimal, e.g. 0.5 for 50%)
Price = the decimal odds you get.

For pre race horse markets the True_Probability can be assumed to be the BSP.

The caveat is that BSP is only 'correct' over large samples as the true price of any given selection is unknowable, it's a horse not dice. But BSP is usually close. In other market types BSP is still a good reference point but deviations from true value can be greater, so accurate EV calculations are harder.

[ForFolksSake]

... and a bet/trade can be +/-ev for any 'price' matched between 1.01 and 1000

Yes.
EV is a measure of the difference between the price you get and the likelihood of the event happening.
Think of it as the average amount you'll win or lose.

Eg heads in a coin toss.
1.9 = -EV
2.1 = +EV
3.5 = even more +EV.

EV per £1 staked = (Price × True_Probability) - 1


Where:
True_Probability = your estimated chance of winning (as a decimal, e.g. 0.5 for 50%)
Price = the decimal odds you get.

For pre race horse markets the True_Probability can be assumed to be the BSP.

The caveat is that BSP is only 'correct' over large samples as the true price of any given selection is unknowable, it's a horse not dice. But BSP is usually close. In other market types BSP is still a good reference point but deviations from true value can be greater, so accurate EV calculations are harder.

.... and for in-play horse markets the True_Probability can be assumed to be "Best Market Price"

[jamesedwards]

... and a bet/trade can be +/-ev for any 'price' matched between 1.01 and 1000

Yes.
EV is a measure of the difference between the price you get and the likelihood of the event happening.
Think of it as the average amount you'll win or lose.

Eg heads in a coin toss.
1.9 = -EV
2.1 = +EV
3.5 = even more +EV.

EV per £1 staked = (Price × True_Probability) - 1


Where:
True_Probability = your estimated chance of winning (as a decimal, e.g. 0.5 for 50%)
Price = the decimal odds you get.

For pre race horse markets the True_Probability can be assumed to be the BSP.

The caveat is that BSP is only 'correct' over large samples as the true price of any given selection is unknowable, it's a horse not dice. But BSP is usually close. In other market types BSP is still a good reference point but deviations from true value can be greater, so accurate EV calculations are harder.

.... and for in-play horse markets the True_Probability can be assumed to be "Best Market Price"

Definitely not. This is where I make all my money.

[ForFolksSake]

Yes.
EV is a measure of the difference between the price you get and the likelihood of the event happening.
Think of it as the average amount you'll win or lose.

Eg heads in a coin toss.
1.9 = -EV
2.1 = +EV
3.5 = even more +EV.

EV per £1 staked = (Price × True_Probability) - 1


Where:
True_Probability = your estimated chance of winning (as a decimal, e.g. 0.5 for 50%)
Price = the decimal odds you get.

For pre race horse markets the True_Probability can be assumed to be the BSP.

The caveat is that BSP is only 'correct' over large samples as the true price of any given selection is unknowable, it's a horse not dice. But BSP is usually close. In other market types BSP is still a good reference point but deviations from true value can be greater, so accurate EV calculations are harder.

.... and for in-play horse markets the True_Probability can be assumed to be "Best Market Price"

Definitely not. This is where I make all my money.

..... True_Probability can be assumed to be "Best Market Price"....

One man's meat is another man's poison

[ShaunWhite]

... and for in-play horse markets the True_Probability can be assumed to be "Best Market Price"

Which best, backing or laying? Can't be both esp with big in-running spreads.

[ForFolksSake]

... and for in-play horse markets the True_Probability can be assumed to be "Best Market Price"

Which best, backing or laying? Can't be both esp with big in-running spreads.

... True_Probability of winning can be assumed to be "Best Market Price"

... True_Probability of a 'loser' can be assumed to be "Reverse Market Price"

[ShaunWhite]

... and for in-play horse markets the True_Probability can be assumed to be "Best Market Price"

Which best, backing or laying? Can't be both esp with big in-running spreads.

... True_Probability of winning can be assumed to be "Best Market Price"

... True_Probability of a 'loser' can be assumed to be "Reverse Market Price"

Btw when you say 'best market price' there's 2 of them. The best back price and the best lay price. And two reverse prices.

But logically you can't have a different chance of winning just because you're either backing or laying.

It''s got a 100% chance of either winning or losing, so the probability of losing is 100% - the probability of winning. The win True_Probability and the win False_Probability (ie losing) must add up to 100.

[ForFolksSake]

Which best, backing or laying? Can't be both esp with big in-running spreads.

... True_Probability of winning can be assumed to be "Best Market Price"

... True_Probability of a 'loser' can be assumed to be "Reverse Market Price"

Btw when you say 'best market price' there's 2 of them. The best back price and the best lay price. And two reverse prices.

But logically you can't have a different chance of winning just because you're either backing or laying.

It''s got a 100% chance of either winning or losing, so the probability of losing is 100% - the probability of winning. The win True_Probability and the win False_Probability (ie losing) must add up to 100.

....it could be said it's analagous to 'wearing two hats' at the same time

[ShaunWhite]

....it could be said it's analagous to 'wearing two hats' at the same time

Not really. The chance of winning is the same whatever side of the bookmakers counter you're standing on. The horse doesn't care what hat you're wearing.

If you want a clue then if it's not best back, and it's not best lay, then could it be in between those, or like pre where it's a price in the future, or maybe it's the LTP.

[ForFolksSake]

....it could be said it's analagous to 'wearing two hats' at the same time

Not really. The chance of winning is the same whatever side of the bookmakers counter you're standing on. The horse doesn't care what hat you're wearing.

If you want a clue then if it's not best back, and it's not best lay, then could it be in between those, or the LTP, or something else.

.... 'backing' and 'laying' is like wearing two hats at the same time

[ShaunWhite]

....it could be said it's analagous to 'wearing two hats' at the same time

Not really. The chance of winning is the same whatever side of the bookmakers counter you're standing on. The horse doesn't care what hat you're wearing.

If you want a clue then if it's not best back, and it's not best lay, then could it be in between those, or the LTP, or something else.

.... 'backing' and 'laying' is like wearing two hats at the same time

It's one hat, then you put a different hat on. They aren't both on your head at the same time.

And if you lay then the person matching that is backing, and visa versa. So what's the fair price?

Anyway that's a puzzle that should keep you busy for a few days.

[ForFolksSake]

Not really. The chance of winning is the same whatever side of the bookmakers counter you're standing on. The horse doesn't care what hat you're wearing.

If you want a clue then if it's not best back, and it's not best lay, then could it be in between those, or the LTP, or something else.

.... 'backing' and 'laying' is like wearing two hats at the same time

It's one hat, then you put a different hat on. They aren't both on your head at the same time.

And if you lay then the person matching that is backing, and visa versa. So what's the fair price?

Anyway that's a puzzle that should keep you busy for a few days.

... in-play you haven't got time to take one hat off and put a different one on, it's both on from start to finish I'm afraid
.... and the horse doesn't care what the True_Probability is of it 'winning' or 'losing' and whether you're 'backing' or 'laying' it if you want to bring the horse into the discussion

[ShaunWhite]

... in-play you haven't got time to take one hat off and put a different one on, it's both on from start to finish I'm afraid

That's why you wear your 3rd hat, the traders hat. The one that says backing and laying are exactly the same apart from the plus or minus sign in win or loss column.

[ForFolksSake]

Redcar 15:25
Sugar Baby - wearing my 'Greening Up' Hat