In 2 Samuel 2, we see David began to deal with the problem of succession to Saul. Abner … commander of Israel’s army now became the effective power behind the throne. He placed Ish-Bosheth apparently Saul’s youngest and least effective son, in authority. Ish-Bosheth’s name means “man of shame.” He was 40 years of age (2 Samuel 2:10) when his father died is an important chronological fact. Since he is not listed as one of the sons of Saul at the beginning of Saul’s reign (1 Samuel 14:49) but is included in the total list of sons (1 Chronicles 8:33). Ish-Bosheth must have been born after Saul became king, indicating at least a 40-year reign for Saul.
Ish-Bosheth had a brief tenure as king, only two years. The fact that David reigned for seven and one-half years at Hebron before he made Jerusalem his capital (2 Samuel 5:5) need not imply that Ish-Bosheth also reigned for seven and one-half years. But this would contradict 2 Samuel 2:10. There may well have been an suspension of normal governing between Saul and Ish-Bosheth, and clearly David reigned for some time over Judah from Hebron after Ish-Bosheth’s death.
From the beginning of David’s reign his real rival in the North was not Ish-Bosheth but his general Abner. As though to clear the air and settle the question of royal succession, Abner and David’s military leader Joab appointed elite troops, 12 men on a side, to engage in hand-to-hand combat at Gibeon. The winners would decide the issue. The nature of the contest is unclear. Perhaps it took the form of a wrestling match which ended up in swordplay. The irregular use of daggers is suggested by naming the place of the contest Helkath Hazzurim or “field of daggers”.