Can a level 52 beat elvarg?

Its highly unlikely and the answer is going to have to be a no.

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EDIT

Yes a level 15 can defeat elvarg, though it would not be easy, and I am not sure you are actually capable of reaching him at level 15 due to quest requirements..

The combat level is a rather poor indicator of a characters actual fighting ability.

For example, a player could only train melee until attack, strength, and defense were level 60. This would put said players level at around 50-60. If the same player decided to start training ranged, even though his combat level would be high, he would not be a powerfull ranger due to him having very low ranged levels, where as a player who just trains ranged and def could have 45 ranged/def/hp and be a lower level, yet have a easier time on elvarg. It would most likely be easier due to elvargs weakness to ranged attacks.