When greening up the calculation used is a simple math’s formula
Stake multiply by entry odds & divided by current best exit odds
Example; A back bet of £50 @ 7.4 and current odds to green up with a lay bet are 3.15
£50 multiplied by 7.4 divided by 3.15 = £117.46 lay bet requied at these odds
Anyone can try this, go on the ladder and place your bet/s and do the calculation above for each selection bet on using the current available exit odds, make a note of these exit odds and the answer you got in your calculation for each selection using the maths above, then making sure the exit odds have not changed click the ‘Green Up’ button at the top right for Bet Angel to do the same calculation and place the green up bets for you, after that check your matched bets – you ll see the same stakes have been used to green up each bet at those odds as what you will of already calculated.
That’s all there is to it nothing fancy or over complicated just a simple formula used whether greening up on the ladder screen, the one-click screen and either pre-play or in-play.
Problems Greening Up In-Play
So why do some new users have problems when greening during in-play – even though the calculations are still done the same way?
The biggest reason for this is because Betfair impose a delay on ALL in-play bets (this includes those placed directly on their site) - this delay also applies when greening up. In-play delays vary from sport to sport but for horse racing the delay is 1 second. So when you click to green up although Bet Angel sends the order immediately to Betfair they park the order for a whole second before placing it on the exchange for you.
This is where the problem starts for those who are not aware of this, the scenario unfolds like this;
A £25 back bet has been placed on a selection, the odds have now shortened in-play and you see a green figure of £5, you click the mouse (to send a £30 lay order to green up at current odds) but it looks like nothing has happened, you click again and again sometimes, even more, all in quick succession trying desperately to submit that green up order. What you have not realised is that each click is submitting further green up orders and any moment now the first is going to arrive in the market followed very quickly by all the rest.
The first order is matched and has greened you up but a fraction of a second later the additional two £30 lay orders you submitted now arrive in the market and also get matched, now you have an extra £60 of lay bets on that selection and its odds are still shortening, you’re quickly seeing your £5 green turn into a horrible red as the odds continue to tumble. This will ensure more frantic mouse clicking trying to green up by sending a back order to get you out before it gets worse, but this multiple clicking will only increase the problem when all these 'greening up' back bets reach the market and get matched. This could go on and on each series of frantic clicking compounding the problem and by the end of the race your scratching your head wondering how on earth you now have a loss several times bigger than your initial £25 bet which you tried to green up for a £5 profit.
How should it be done?
The solution to this (and this applies to everyone including those using automation) is when you submit a green up order in play WAIT between each click of the mouse to allow the first bet to reach the market. When it does you will see yourself greened up if matched, or if the odds have moved you will see it in your ‘Unmatched bets’ area and on the ladder screen.
If you can see it ‘unmatched’ you can safely click again as a new ‘green up’ order will automatically cancel any existing unmatched bets in the market as soon as the mouse is clicked (so it will be long gone before the next reaches the market) meaning you’re in no danger of ever having more than one green up order matched and experiencing the problem detailed above.
Something else to be aware of
With the in-play delay, the speed at which odds are moving in-play and because Betfair always match orders at the best available odds when they reach the market if you look at the example used at the very top of this post where trying to green up at 3.15 with a stake of £117.46 (if it matches at these odds it will achieve an equal green) but since clicking to ‘green up’ if the odds have continued to fall during the in-play delay they could be at 2.56 when the order actually reaches the market, so you have now greened up @ 2.56 using a stake of £117.46 which will mean you have greened up but it won’t be completely even across all selections so in-play it will often require another green up or maybe more to equal everything – just be sure to allow enough time between each and just as above you will have no problems.
Other sports in-play
The same principle applies to all other sport when trading in-play, for example football has a delay of 5-12secs (depending on the league) so you need to allow even longer between submitting each ‘green up’ order to allow the previous to reach the market and just as with the horse racing example above if it arrives and is unmatched because the odds have moved as long as you can see it in the unmatched bets area or on the ladder you can safely click to green up again and that original order will be cancelled when you do so, thus safeguarding you from having two orders matched by accident.
If you follow the above then you won’t have any in-play greening up problems.