Statistical analysis on online betting industry?

Hi! i'm currently working for an online betting company and i would need some help on how to come up with risk indications. I believe some statistical tools may help me assess the gravity of risk of a certain event or user.
For example:
1. a certain player bets on an average of 100 per bet for the past week then suddenly he bets 2000 on one hand. What is this indication? what statistical tool can prove that the value is significantly high and is an outlier and can be a possible fraudulent.

2. There are different kind of games and how can i come up with the correlation between the type of game and the winning chances of users.

3. how can i compare the betting behavior of different players. For example, the game is a simple one number lottery, choosing numbers from 1-5. player A played 5 games.
1-game type A- chose #2 - Win
2-game type C- chose #4 -Win
3-game type B- chose #4 -Lose
4-game type A- chose #1 -Win
5-game type B- chose #5 -Lose

While player B played 4 games
1-game type A - chose #2 -Win
2- game type C - chose #4 - Win
3- did not play
4- game type B - chose # 3 -Lose
5- game type A - chose # 4 -Lose

How can i compare the play/betting behavior of the two players? is there statistical way to show the similarity on the betting behavior of the 2 players and can be a possible fraudulent? including the way that they picked the numbers.

This would be a very big help. thanks!