Something I've been looking at , and finally had a go at today. I think the idea could have merit with many different methods of selection or ratings but in my case my original selections are pre post favs.

The initial idea is to back the selection @ top fluc or if at MR or SR @BOB well b4 the race.

OK so now if 1st or 2nd fluc are better than the original Pre Post price one can choose one of 2 ideas, first, just let the bet ride, as statistically Pre post favs overall will lose about 15% on T/O so if you have secured better than that that then you should win overall, OR you could make a book on the first 3 or 4 rated, as you already have a minimum price on the fav.

Now if 1st or 2nd fluc is below the pre post price, then you can lay off on betfair without too much damage or even a slight profit (in many cases)

eg today at Ascot race 2 pre post fav race 2 -1 $4, Top Fluc = $7