[Mean]

He means:

pawn Код:

switch( GetPVarInt( killerid, "kills" ) )
{
    case 2: // 2 kills
    {
        // Stuff here
    }
    case 3: // 3 kills
    {
        // stuff here
    }
    // ETC
}

Instead of

pawn Код:

if( GetPVarInt( killerid, "kills" ) == 2 )
{
    // Stuff here
}
if( GetPVarInt( killerid, "kills" ) == 3 )
{
    // Stuff here
}
// ETC

I prefer IFs, I use switch only in dialogs and stuff, since it's just abit faster.
Also, you forgot to put OnPlayerDeath

pawn Код:

SetPVarInt( playerid, "kills", 0 );

So if player dies, his spree gets restarted.

EDIT: Nevermind, you reset it in OnPlayerSpawn..