He's using math correctly you aren't. 1.0 is base average where suicide doesnt count against it. Where it does it falls into negatives as an average. A negative score can be an average equal scores arent always equal. Its like taking a test you start at an A for every thing wrong you go down, killed by another, everything missed you go down, kills from yourself, and everything you get right moves you up or keeps you above, killing others. It only doesnt seem right because not every game has it where suicides count against you.