Awesome Joe , reminds me of this post I made not very long ago :

The formula for Z-score is :

Z = (W - (N*P) ) / squareroot (N*P * (1 - P) )

W - Total number of wins.

N - Total number of bets placed.

P - Probability factor of bet actually winning.

A Z-score of :

1.0 means 16% chance win was due to pure-luck.

2.0 means 2.3% chance win was due to pure-luck.

3.0 means 0.13% chance win was due to pure-luck.

Anything higher than 3 is a bonus and implies a fantastic system/method...

Example :

High Low EC betting strategy

Wins (W) - 30

Total bets ( N) - 35

Probability of winning (P) - 18/37 = 0.4865

Substitute those values into the Equation below:

Z = (W - (N*P) ) / squareroot (N*P * (1 - P) )

Z = ( 30 - ( 35 * 0.4865) ) / squareroot ( 35 * 0.4865 * (1 - 0.4865) ) = 4.387

We round it off to 4.39 ... So a Z-score of 4.39 great stuff...

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