This is called a royal psalm because of the emphasis on the role of the anointed- vs. 6- and the king- vs. 9. 

Key words in the Psalm:
"answer" in vs. 1, 6, 6, 9
"victories" "saves" "saving" or "save" are all from the same root word in vs. 5, 6, 6, 9
The word "name" is used in 20:1, 5, 7. 

The people had great hopes for the king- II Sam. 21:17; Lamentations 4:20

The king's responsibility is to trust God and to remember Him- vs. 7
Some trusted in horses and chariots but battles were won by God's power
Psalm 33:16-17, 20
Psalm 44:2-3
Deuteronomy 20:1-4
Joshua 24:11-12