An older version had more bullets so a score of 4750 could drop down to 3900 right before you died, which I thought was ridiculous, so I lowered the bullets. If you keep shooting, you could get hit by two bullets in a row and not notice that you dropped 100.

EDIT- and in the old version, if the bullets hurt Jazz, no one would make it past 1500.
And my highest score is 6550, gj on nearly getting 8000 LF.