Implied Odds

In the last post I played a gutshot aggressively over two streets against a calling station - the lowest EV play IMO. At the time I thought that just check folding may have been best but I decided to put some hands into pokerazor to find a threshold for implied odds. I simplified the given hand and found that providing we could reliably make better than approx (20 x bet to call) on later streets then we could reasonably call to hit our gutshot. In other words if it costs less than 5% of the effective stacks. It's a long time since I studied any implied odds maths because in full ring it's generally best just to muck gutshot straight draws. But they are a hand we will get quite often and are seriously worth playing in heads up. So the little rule of thumb I'll use from now on is this 5% figure. Easy to stick to and shouldn't get us into much trouble. Of course for any additional outs we can increase this and use our intuition about how much it might be safe to call. We could also double this figure for flush draws and open ended straight draws ie if it costs less than 10% of effective stack size we call, otherwise fold. Really useful rules of thumb I think.