Hi Malaguti! (and the rest)

That's indeed what I mean. As a mroe concrete example, I've added two pictures:

First one, example of an almost perfect downtrend:

Second one is a lot less "clean":

So the actual question is, is there a way to measure if some price trends "better". As NVP put it: why trade the sluggish ones?

then I'm sure there are a few different ways of approaching the same thing.

personally, I'd try to create an indicator and your inputs could be as Tomorton suggested..the number of closes below an MA for example could give rise to a simple count function..a bit like the below would be the result

compared to the not so trending one

my inputs was actually the number of highs produced (given that its a higher high, higher low that defines a trend..for me at least) but the same could have been done with closes below a MA as Tom mentioned.

This would be the most straight forward..the higher the count, clearly the better the "trendability" as it were

the other way you could do it could be the slope of the linear regression of the price over a period of time..the higher the slope, again the trend..however I'm not sure you can get an actual measurement of it..statistical as you mentioned earlier. so its the least best option in my opinion assuming you dont want to be eyeballing every chart, hence the reason for a statistical method i assume

as for your specific example of a nice clean trend (id argue its not clean at all by the way) you could simply have a condition that todays close is less than yesterdays, is less than the day before and could easily probably be written as

C<C(1) and C(1)<C(2) etc

so you see there are probably a few ways..you might want to explore each of them and see which one works for you. there are loads of free charting software that allows you to create your own indicator/filter etc and took me a few minutes to write one so you could easily do the same im sure

hope this helps