A tick offset is the term given to placing an opposing bet automatically, immediately after your original bet has been matched in Betfair.
The first thing to understand is that a "tick" is the next available Betfair price, so an understanding of acceptable Betfair prices is required.
The table below shows an example of what a one tick offset would produce, placing an original bet between [1.01] and [50.0]. After 50 the price increments are in 10s all the way to the maximum price of [1000.0].
Once you have an understanding of the price increments you can then tell the trading app how many "ticks" you would like to place the opposing bet at.
As well as being able to specify a number of ticks for the opposing bet you can all get applications that allow you to specify a percentage difference between the two bets. Therefore, placing a back bet at [8.0] and asking for a tick offset of 50% would place you lay bet at [4.5] - this would be the same as asking for a tick offset of 25 for your back bet at [8.0].
Again, the benefit of using a trading application is that it gives you the flexibility and control to place your tick offset bets in a way that suits your trading style.
Once you have decided on your margin you then just need to tell the application how you would like it to place the opposing bet - create a green book or leave you with a free bet on the selection. The application will execute your instructions and as long as both bets are matched you will have achieved your required outcome.
For more advice on tick offsetting, check out this video (the software used in the demonstration is Betting Assistant)
For a selection of Betting Apps for Betfair.com please see the Betfair App Directory.
Check out Alan's piece on Auto Refresh and Greening Up