Enhanced 'green-up' capability

[The fish]

I would like to see an enhanced or alternative ‘green-up’ function: the current function is not aligned to my needs nor, it seems, those of a number of other traders. (See forum “Greening Up in Play DOUBLED MY LIABILITY!?!” for further comments.)

My objectives in ‘greening-up’ are (as well as cancelling outstanding unmatched trades) to make my worst possible outcome as good as feasible. The example below shows that on occasion (actually quite often for cricket, the sport I trade most) the current function offers to level out at a position worse than my current worst position. The example below was in a stable and liquid market – test matches are usually both, in between balls. ‘Green-up’ offers me -£43: in fact two simple trades left me with a level position of -£23 or so.

Green-up example.JPG

At a minimum it seems to me that ‘green-up’ might sit on its hands if it cannot improve the current position. One can easily imagine a simple algorithm to do somewhat better, though – if the positions on each ‘runner’ are P1, P2, P3… Pn, from worst to best, one can place a lay on P2 to 'equalise' with P1, then a lay on P3 to ‘equalise’ with P1 and P2, and so forth until a lay on Pn results in a final position that is ‘more or less equalised’ (may be hard to achieve) and is between P1 and Pn in value. In the simple case of a two horse race one might instead always place the equalising trade (back or lay) on the favourite, where liquidity is usually far better.

There are no doubt more efficient algorithms that you can propose, but the key point is to achieve a position where the worst position is as good as feasible. I understand that other may have different ‘green-up’ needs – I would be quite happy if my proposed capability were an optional setting for those with my needs.

[Crazyskier]

Hi Fish.

It says 'form invalid' when I try to vote yes?

[Crazyskier]

I've tried logging in and out and every time I vote it says invalid, but please count my vote to sort out the flawed algorythm that is used by BA to green-up in play. Other software including Betfair's own do NOT have this flaw.