On the score screen, what is 'Best Shot'?

I usually get ~780 for my best shot but my teammate gets over 2,000. However we can't figure out what it is. Is it damage done in a single shot? How can you get such a high value?

I'm playing Zombie Army Trilogy if that matters, there is no tag for it but it includes nazi zombie army 1&2.

Solution 1:

Figured it out, it's actually number of points for a single shot. I managed to shoot three zombies in the head with a single bullet (they were lined up) and it awarded me 1860 points, and on the final screen this was my 'best shot'.

You also get a high number of points if you grenade kill multiple zombies in the same explosion.