Following your analysis, you will try to estimate a probability that the bet will pass. The trick is that bookmakers also estimate the probability that a bet will pass.
Well yes, when a bookmaker sets an odds, he estimates the probability that a bet has to pass. Basically, the smaller the odds (closer to 1) the more likely the bet is to pass.
A value bet is when you feel that the odds offered by the bookmaker are too high for you. At this point you think the bet has a better chance of going through than the bookmaker thinks.
A concrete example ? Ok imagine you want to bet on Bayern Munich winning at 1.50, and you estimate their chances of winning at 70%. Is this odd a value bet?
With a table like this you see that for a probability of 70%, your odds must be greater than 1.43. Our odds at 1.50 for Bayern is therefore a value bet.
If you want to calculate a valuebet more precisely, I refer you to the linked article, which does the job very well. The goal is for you to understand the principle of value betting.
So of course it is difficult to best estimate the probability that a bet will pass, not to mention the risk of making a mistake in its analysis. But betting on valuebets is the best technique, because you take advantage of the bookmakers’ small mistakes.
Don’t dream, bookmakers make few rating errors. There is therefore little value betting, and when there is, the betting sites do not hesitate to readjust the odds.
The value bet is rare, but when you find it it’s worth it.