Muhammad Ibn al-Hassan inTop of the Chain of Narration of the Book Kafi

In 103 chains of narration of the book Kafi, the name of Muhammad Ibn al-Hassan has been mentioned as the first person. Late Sheikh Kuleini has quoted 1512 narrations through "a groups of narrators" from Sahl Ibn Ziyad. Since `Allamah has quoted from Sheikh Kuleini, one of the person who is present in "a groups of narrators" is Muhammad Ibn al-Hassan. After examining nine narrators who may possible to be Muhammad Ibn al-Hassan, the conclusion is that "Muhammad Ibn Hassan Saffar" and "Muhammad Ibn Hassan TaieRazi" have the most narrations. MuhaqeqBrujerdi and AyatullahShubeyri has accepted the latter possibility and Sahib Wasail, FazelEstarAbadi, MuhaqeqeKazemi and some others have strengthened the first possibility. It seems that the first possibility (Saffar) is so weak and there is no certainty about TaieRazi. Anyhow, even if we cannot determine Muhammad Ibn al-Hassan, his narrations due to being narrated by majority of narrators would be correctable.