1. General

Pre-game betting is a very interesting area for profitable investments without remarkable uncertainties, because the fluctuations of the odds are very small during the pre-game period.

A well known pre-game trading method in Betfair Exchange market is the back to lay in Under 2.5 market. A couple of days before the game the price of Under 2.5 may have an odds value that would start to decrease as we are getting closer to game day (figure 1).

This is the case for an trading by placing a back bet couple of days before the game as an entry point and then placing a lay bet 10min before the game starts as an exit point of trading. The question is how to recognize which is the appropriate odds value of Under 2.5 market that will start to decrease, as we get closer to the game.

Figure 1: Under 2.5 odd decrease as we get closer to the game

2. Prediction of Trend

A simple but very effective rule to recognize fluctuations for Under 2.5 market is to predict the odd between the two teams by using pure historical records using TimeStat Software and then compare this predicted value with the corresponding value of Betfair exchange market.

Let’s assume that an Under 2.5 market for a football game that starts on Sunday, has a back value in betfair exchange market equals to “Under 2.5”=1.80 on Tuesday (five days before kick-off). If by using TimeStat Software, we predict a value for Under 2.5 equals to 1.60 that probably means Betfair value will start to decrease, as we get closer to game day.

Odds value is correlated with probability of the event with the rule:

O(x) =1 / P

Where:

O(x)      : Odd value for the event

P          : Probability of the event

Table 1 shows the above assumption comparing bookies or exchange market odd OB with the predicted odd value OP from TimeStat Software. When OB > OP the predicted probability for the event to happened is higher than the assumed probability related to bookies price. In this case, it is assumed that market has a profitable odds price for betting, called “added value”. Concerning pre-game trading due to “added value” compared with the predicted one, OB may start to reduce as getting closer to the game date. That seems to be a great change for trading with placing a back bet as an entry point some days before the game and then placing a lay bet a couple of minutes before the kick-off as an exit point of trading.

When OB < OP the predicted probability for the event to happened is lower than the assumed probability related to bookies price. In this case, it is assumed that market has not a profitable odd price for betting, called “low value”. Concerning pre-game trading due to “low value” compared with the predicted one, OB may start to increase as getting closer to the game date.

Table 1: Rules for recognize profitable betting or Pre-game trading

Again, this may be a chance for a pre-game trading by placing a lay bet as an entry point a couple of days before the game and then placing a back bet a couple of minutes before the game as an exit point of trading.

3. Conclusions

A simple but very effective rule to recognize fluctuations for Under 2.5 market is to compare bookmakers' odds with predicted odds from TimeStat software. The difference between these values makes sense for placing or not a bet or to start trading before the game. When OB > OP the predicted probability for the event to happened is higher than the assumed probability related to bookies price and when OB < OP it is the opposite. In every case the most important thing is the accurate prediction of OP.