This verse follows the standard formula for introducing kings of Israel (and later also of Judah) in the books of Samuel, Kings, and Chronicles. But this verse contains one of the most difficult textual problems in the book of 1 Samuel, if not of the whole Bible.

The Masoretic Text literally says “Saul was a son of a year in his reigning and two years he reigned over Israel.” Obviously there are two errors in the Hebrew text as we have it today: (1) Saul was not one year old when he became king, and (2) he reigned more than two years. Interpreters and translators have followed many solutions to this textual problem:

(a) Some translations, following the example of the Septuagint, omit the entire verse (so Good News Translation, Bible en français courant, and Parola Del Signore: La Bibbia in Lingua Corrente).
(b) Some translate the verse but leave blank spaces as in Revised Standard Version (so also New Revised Standard Version, New American Bible, Osty-Trinquet, and La Bible Pléiade).
(c) Others leave only the first number blank. Compare Traduction œcuménique de la Bible: “Saul was … years old when he became king and he ruled two years over Israel.” Traduction œcuménique de la Bible, however, includes a note saying that two years is certainly not correct. New Jewish Publication Society’s Tanakh, Fox, Stuttgarter Erklärungsbibel, Nova Tradução na Linguagem de Hoje, and Die Bibel im heutigen Deutsch follow the same solution as Traduction œcuménique de la Bible.
(d) Some follow the first-century Jewish historian Josephus and Acts 13.21, and claim that Saul ruled for (about) forty years. Compare New International Version “Saul was thirty years old when he became king, and he reigned over Israel forty-two years.” The “thirty years” is based on a few late Septuagint manuscripts.
(e) Revised English Bible follows the Greek manuscripts, which say that Saul began to reign when he was thirty, and then conjectures that the number of years he ruled was twenty-two: “Saul was thirty years old when he became king, and he reigned over Israel for twenty-two years.”
(f) Nueva Biblia Española leaves the first number blank, stating in a note that the original lacks the number. But then Nueva Biblia Española says that Saul reigned for twenty-two years; however, it has no note indicating that the number twenty-two is a guess.

Solution (d) above may seem the best at first glance, but a major problem with this is that early in his rule Saul already has a grown son able to command troops (see verse 2). Therefore Saul must have been older than thirty when he became king.

Critique Textuelle de l’Ancien Testament gives an {A} rating to the Masoretic Text. As for the first number, Critique Textuelle de l’Ancien Testament suggests that the author left a blank space, not knowing the exact age of Saul when he began to rule. And as for the second number, Critique Textuelle de l’Ancien Testament defends the number “two,” suggesting that Saul reigned two years with God’s blessing, that is, he reigned two years before David was anointed (see 16.13). If translators follow the recommendation of Critique Textuelle de l’Ancien Testament, it may be helpful to indicate in a note the possible sense of the words that Saul “reigned over Israel for two years.”

Quoted with permission from Omanson, Roger L. and Ellington, John E. A Handbook on the First and Second Books of Samuel, Volume 1. (UBS Helps for Translators). New York: UBS, 2001. For this and other handbooks for translators see here .