I agree. I think the chart works well according to the estimates I've been given and I'll definitely keep referring back to it. I appreciate having access to it
.The more I learn about Yorkies, the more I realise each one is so individual that you just can't tell anything - especially when it comes to size. One of the breeders I spoke to said one way she knew she'd get a 'smaller' boy or girl was if the nose and paws were relatively small at 8 weeks. I think determining size for any dog is a real variable (diet, bone structure, musculature etc.) but according to the calculations I've already been given by a number of UK breeders, the chart is completely accurate at the 8 and 12 week mark and my husband, who is a statistical mathematician, says that the chart's extrapolation scale makes complete sense from a mathematical point of view (but that doesn't always work I guess in practice; which is why I was never interested in maths at school! Hahaha! Stupidest school subject ever!)