Thanks for the reply! In the Merciless mod, it was also in the 'spawnPlayer', so that's why I thought it should be done every time a player spawns.
But if i add the variables to the dm.gsc -> self thread cod2\_player::_KillSpree(attacker,killspree);
I get a script compile error: uninitialised variable 'killspree'
So I guess it needs to be initialised somewhere before? (again sorry, my knowledge about scripting is very limited)