Yearlings predicted height?

[R.A.H]

How accurate is this method in estimating a yearlings height?

http://www.ultimatehorsesite.com/info/stringtesting.html

 

[tallyho!]

I tried the mid-knee to coronet and it said 17inches... there is absolutely no way my filly is going to make 17hh....

Another one is - add two hands for a yearling, one hand for a two year old. This said my filly would make 15.3. This one makes more sense as her dam is 15.1 and sire is 16hh.

 

[Meowy Catkin]

Pretty good (elbow to fetlock method) and it will give you a 'ballpark figure' but it's not an exact science especially if you use a stretchy leadrope.