Why does the Sequel say the book is based on 2,100+ meta-analyses?

Answer: The evidence in this book is based on 2103 meta-analyses. The reason for 2100+ in the title is that in most cases, only the average effect per meta-analysis is included, but where there is more than one set of influences within a study, these are also added (208 meta-analyses include more than one effect; so the total sample is 2,313).