msjennifer, on 2018-August-23, 02:37, said:
They justify that by pointing out that they have 12 HCP which is 2HCP more than the arithmetical average of 10 HCP.
There is nothing wrong with learning from books - I have quite a large collection.
There are some good books around which will help you develop your judgement around hand valuation and move on from a simple counting exercise. I recommend Hand Evaluation in Bridge - Brian senior. The book is now 20 years old, but I certainly found it very helpful and it improved my bridge judgement. There are other books that I am sure others have found helpful.