Understanding the initial direction of the Over or Under goals markets on a betting exchange when the game goes in-play and the different speeds that the market moves is key to judging your risk when trading. Grasping this and understanding what happens when a goal is scored is half the battle to making profit in these markets.
As a game goes in-play the probability of a goal being scored begins to diminish when you are trading the Over goals market which means that the odds will increase as the minutes tick away. Depending on which Over market you are attempting to trade, when a goal does go in, the odds will take a very steep drop to a level where the probability of the market being fulfilled will reflect in the odds depending on what time the goal was scored. For instance If you had laid the Over 2.5 goals and the first goal went in after 5 minutes then there are 85 more minutes of the game left for the remaining 2 goals to be scored and the probability of this happening will reflect as very high and the odds will plummet to a point which would put you into a loss position in the market. If, however, the first goal wasnt scored until the 85th minute then the probability of 2 more goals being scored in the final 5 minutes is very low and the movement in the odds would be slight, if at all.
To demonstrate this visually I am going to use a smart bit of software called BetAngel and a feature in the program called “Soccer Mystic”. This will “predict” the odds during a predetermined game if or when goals are scored. There is a game tonight in the English Championship between Barnsley and Swansea City and for no other reason that it is first alphabetically will serve my purpose admirably.
At the time of posting this the predicted lay odds on the Over 2.5 goals market is 1.91. While this is just a predicted odds level at kick-off the market can be different depending on factors such as team sheet announcements, but for the purposes of this it will suit. If we say that we have a lay bet of £5.00 at odds of 1.91 this would give us a liability (total ammount we can lose) of £4.55 at kick-off. We can use “Soccer Mystic” to see our profit/loss should a goal be scored in the fifth minute. The screen shot below shows the predicted odds if no goal is scored in minute 5 and the predicted odds if there was a fifth minute goal

As you can see we can determine our risk if there was a goal in the 5th minute and this would be a loss of £2.08 if we traded out. In the next screen shot Soccer Mystic also gives a visual representation of how the market “recovers” as the match progresses and can give us an indication as to when we could trade out for no loss if while watching the match we ascertain that the first goal was a fluke i.e. own goal or a lucky fumble in the box and decide to let the bet run to our predetermined exit point.

The predicted odds are shown by the red line in the graph and as you can see after the first goal going in at the 5th minute the odds plunged to 1.34 but then as the game progresses and no other goal is scored the market recovers slowly to rise after about 35 minutes in-play time to a break even point where we can exit the trade for a no loss/profit. In the graph the horizontal blue line is the “profit” line and when we are laying the market when the red line is above the blue a profitable trade is possible.
As with all things betting or trading research is the key and you may have noticed that I mentioned a predetermined exit point. After doing some really basic research on this game tonight I came to a decision, provisionally, that the first goal probably, using previous games as a guide that perhaps, barring fluke goals, the first goal might be some time after the 17th minute. Using this as our control point we can set out exit point at 15 minutes win or lose

In the screen shot above I have pointed the cursor at 15 minutes and in the ringed box shows us that the predicted odds after 15 minutes when the first goal was scored after 5 mins would be about 1.49. This would leave us in a losing position but if we were right and the next goal went in at minute 17 then our loss would be greater. If of course no goal was scored and we trade out at 15 minutes Soccer Mystic can show us our predicted profit as shown below.

I am sure you are thinking “what if I want to back over 2.5 goals ” then the opposite applies and if you had backed this market at the odds shown and a quick goal was scored then the odds would move dramatically in your favour to enable you to trade out at a profit. as shown below.

We would exit this trade at this point for a £1.93 profit and this would be great but again when we go into this trade we need to pick an exit point and having done the same research we think that the first goal will be at about 17 minutes how far past this point do we go if no goals are scored. If we pick our exit point at say 25 minutes and no goals are scored Soccer Mystic can show us what sort of loss we would expect to take as demonstrated below

As you can see an overall loss of £1.95 would be our exit loss.
To summarise if we are laying an “Over” market the odds rise steadily in our favour and continue to provide the potential profit but as soon as a goal is scored our profit potential vanishes to be replaced with the very great risk of a losing trade, on the flip side, if we back the “over” market then our position is of a losing trade until a goal goes in and the earlier the better.
Just for fun there are 7 championship matches tonight and the average time for a first goal this season in the championship league is 32 minutes the following 7 screen shots show what you could expect to win if you laid the Over 2.5 goals market and each game remained goalless until this point.







These 7 screenshots predict the odds and probable trade out profit if there were no goals in their respective games



