Any top 50 list with Iverson on it and McHale off of it is flawed.
McHale is on the list.
I'd also rate career averages higher than career totals in terms of greatness, but my definition may differ from yours. And while this may be difficult, number of years on a leaderboard (whether you pick top 5 or top 10) for a given category would be the best determiner of all. In other words, number of years Parrish was a top 10 rebounder is more important than his career average, and both are more important than his career total.
I thought about this. I decided that racking up many career points, rebounds, blocks, assists, steals etc over many years is more impressive and indicative of greatness than playing for a shorter amount of time and having a higher average.
A player could be in the league for only a year and average 30 ppg (however unlikely) and be high on the list even though they made a relatively small impact on the league.
Intellectually I like this, but there are fundamental flaws. Why are rings only worth 5 each? Jordan is considered untouchable in the debate largely because of his 6 rings, and it's only 30 of his 867 points (3.5%) in your formula. Also, posthumously declaring awards that weren't offered is totally biased and Finals MVPs do NOT always go to the best player on the team (Cedric Maxwell, James Worthy, Tony Parker come to mind).
You're probably right about posthumously declaring awards, although I would still argue Russell deserves it. I'm considering just removing that part and putting Russell at #4, with an asterisk.
As for the championships argument, the thing that gets me with that one is that guys like Eddie House, Adam Morrison, Darko Milicic etc all have more rings than Karl Malone. Are they better players than him? Not nearly.
Also, Karl Malone gets placed higher than Bird and Kobe because he played at a very high level for a really long time. This is the nature of giving players points based on their rankings in statistical categories. Players who were great in a number of categories for longer get the advantage over those who were great for a shorter time (Bird) or truly exceptional in only one or two areas (Kobe).
Some others that we're obviously arguable...but [dang] Reggie
Reggie was somewhat a surprise to me as well, but there a few things to consider --
He ranks highly in win shares and playoff win shares because he led the Pacers deep in the playoffs for so many years. I believe he also got some points for steals, and of course 3 pt makes and 3 pt percentage, as well as true shooting percentage.
He benefits from the fact that the league has only recently (in the past 10-15 years) become a very 3 point oriented league, meaning that there haven't been many players like himself with very long careers who racked up long range shots.
Jason Kidd also benefits from this (he's #3 all time in 3 point shots even though he didn't shoot well early in his career).