No you&#x27;re right, I read&#x2F;skimmed it cover to cover, but that doesn&#x27;t do that book justice. I didn&#x27;t do a single exercise and I really focused on the sections that were relevant to what I was doing (Random Forests, testing&#x2F;validation). The author recommends maybe 4 or 5 chapters as required reading in the forward so I read those much more thoroughly, but again, skipped all of the exercises and the appendices. At the end of the day though, I&#x27;m not going to be implementing these algorithms, I&#x27;m just using existing libraries so I couldn&#x27;t really justify the year+ of effort to go in depth on everything. That book is also a summarization of a lot of techniques. If you wanted more depth, I wouldn&#x27;t think Elements of Statistical Learning is the book for it. I&#x27;m hoping to get fill in some of those gaps through reading Optimization Models a bit more closely.