QUESTION FOR STATISTICIANS AND ANALYSTS

[lmf21734]

Dear All

I am building a strategy around specific occurrences in football and here is the question.

If Team 1 has a 60% chance of scoring in the the first 20 minutes of a match (based on matches they have played in the season) and a Team 2 also has a 60% chance of scoring in the first 20 minutes of a match then if these 2 teams play against each other is the statistical chance of a goal being scored in the first 20 minutes the mean of the 2 percentages (so 60+60)/2) which is still 60% or is it higher than 60% because you are now bringing 2 likely scenarios into the same event.

Appreciate your thoughts as I am not sure of the answer

MEL

[Euler]

You need to work out the chance of neither of them scoring then find the inverse of that joint calculation.

[Euler]

Team A scores = 60% not score = 40%

Neither NOT = .4*.4=.16

Therefore, no team scores =16%

Any team to score = 84%

[gazuty]

Team A scores = 60% not score = 40%

Neither NOT = .4*.4=.16

Therefore, no team scores =16%

Any team to score = 84%

Ahhh stats and logic. Love it.

[burntheory]

I'm guessing if Team 1 has only conceded a goal in the first 20 mins 10% of the time, and Team 2 20% of the time, the implied probabilities are going to change. Now it looks like there’s a 72% implied probability that neither team concedes a goal in the first 20mins. That leads to the implied probability of a goal to be 28%.

Averaging to two implied probabilities (of a goal) gives a 56% chance of a goal in the first 20mins. As an approximation, this ‘feels’ better than 84%. Whether it actually is better is another matter…