The aim of our research is to answer the question why top journals are “top”. This paper presents the results of the first step of our research, in which we investigated whether or not the top journals stand out among 12,323 journals in the JCR 2020 list in terms of various factors such as publishers, citable items. The results showed that top 20 journals stand out in terms of their subject categories and publishers. At this point, it would seem that the subject category is more decisive than the publisher. Considering the Springer Nature example, publishers that stand out in the top 20 have more publishing activities in the subject categories that have more top 20 journals. Although the top 20 journals are located in the highest 5% of all JCR journals in terms of the number of total citations, except five review journals their distribution by citable items differs greatly. Especially for the review journals, the number of citable items is at the lower end of the distribution. It should be noted that more than half of top 20 journals locate as outliers among all journals in terms of the share of articles in citable items. This is mainly due to high density of review journals in top 20. The behaviour of journals regarding cited and citing half-life is different. They generally locate in the boundaries of middle half of all JCR journals in terms of cited half-life. However, they are in the first shortest quartile of citing half-life. Note that the five journals in top 20 from Engineering & Technology and Multidisciplinary subject categories have shortest citing half-life in comparison with the other JCR listed journals in these disciplines. We aim to investigate top 20 journals more deeply in the on-going second step of this research project considering the previous JCR years, and to understand the reasons for the location of top 20 journals among all JCR journals. In this second step, JCR 2020 top 20 journals’ change of ranks, subject categories, and publishers between 1997-2020, types of journals and documents, citation skewness and number of articles that provide impact factor advantage, number of authors and international collaborations, affiliations, and funding information will also be considered.