True reflection of odds - survey.

As an average: 10
As individual events: 7

You wdn't need to 'rate' it--this is something you cd find out. One implication is that you shd do everything you can to back at better than the bf SP.

average more like 8.5-9 for me. too many cases where big positions distort prices for it to be higher than that.

Whatever it is, it will get closer and closer to 10 over time.

Placed 100 £2 bets on Horse Racing over the last 9 days. After 100 bets £0.59 down - Got to say 9.9

not sure I agree with that, Investor. many BF markets don't really exhibit a couple of the key criteria of truly efficient markets.

firstly, a lot of minor markets don't have enough players involved to find a true level.

secondly, even the main markets can be distorted by one big player. eg, the liverpool match odds market the other night. watching it in real time, you could reasonably infer that most of the activity judged in terms of actors was trying to push the liverpool price down. but it couldn't break through a certain level because one player was dripping in 10K at a time and it was enough to absorb  all the pressure.

I agree with Investor, it's surprising but also humbling as it lets you know how to make money!

viva, looking only at liquid markets, winners improve efficiency and losers (who lose more than just commission), make markets less efficient.

Over time there will be a wealth transfer from big players who move the price away from efficiency to big players who make the markets more efficient (with a few people in the middle picking up crumbs). To some extent some inefficiency may remain, perhaps due to bookies sacrificing a small portion of their margin to hedge etc.

Minor markets may not have a lot of money sloshing around, but that just gives more scope for improvement. The half time score market in football for instance, is almost as efficient as correct score market nowadays. A couple of years ago it was nowhere near. Key evidence for this is that in 2009 I made a lot more in this market type than I do now, despite having only a fraction of the funds I have available now. If I graph this, I can see the cumulative profit levelling off, clearly showing that profitability is going down. An increase in market efficiency is the cause of this.

viva, looking only at liquid markets, winners improve efficiency and losers (who lose more than just commission), make markets less efficient.

Over time there will be a wealth transfer from big players who move the price away from efficiency to big players who make the markets more efficient

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that's all true, but assumes a closed system. in reality there is a constant interplay with other external factors. it's not hard to envisage a scenario where, eg, one dominant player in a liquid market is actually laying off money taken at worse prices elsewhere, and simultaneously becomes more of a dominant player in high volume markets and more of a distorting influence on prices.

the more I look at BF's most liquid football markets, the more powerfully it strikes me that they don't exhibit some of the key conditions of truly efficient markets.

also, imo it's false logic to assume (as another poster does) that if a large number of random bets more or less break even minus commission that proves the markets reflect true value. it actually proves that the overrounds are tight, and could just as well be the product of randomly taking good and bad value.

that may seem an esoteric point - but actually I'd argue it's incredibly important. because it implies that the search for value in mature BF markets isn't pointless, and there are major edges that could be potentially uncovered.

There are huge edges staring us in the face every single day, we just probably don't know it.

presidente is correct, in that BF markets aren't closed, zero sum games.

Discovering this was my main route to making substantial sums here.