I posted this in the "Quality of Opposition" playoff thread but LAL1947 mentioned posting it over here so I am.
...I just recently did a bunch of work on great players and the level of competition they faced relative to how great their own team was. I took the SRS of their own team and compared it to their opponent in every playoff series they played to get a feeling for who was most favorited in their series and who faced the biggest uphill climbs. Positive numbers mean you are the favorite, negative you are the underdog.
The following is just the average series differential over a player's career.

The top of the list isn't crazy, as it's basically the guys who played with the most talented teammates in nba history. Their average series was as a 3-4 SRS favorite, which is a huge advantage. Shaq shows up in the middle as probably the biggest regular season switch-flipper in history, regularly slacking off in the regular season before dropping 30/15 in the playoffs. And at the bottom, being a complete playoff outlier as usual is Hakeem. As a Rockets fan, I figured he would look impressive for overcoming the odds, but I didn't expect him to be this far down the list. He's wedged between guys like Wilkins and Melo, who each won 3 total playoff series in their entire careers. Hakeem made the finals 3 times and won an incredible 10 series as an underdog.
Maybe not that different, but the following shows the average differential in series a player won or lost.

We see once again what charmed lives guys like Curry, Bird, Magic, and Duncan lived, being huge favorites when they won and being near even or even having the advantage in their average series loss (Bird especially, who's biggest underdog series of -1.71 isn't even as bad as some players' average series). Harder to get a feel for Russell since he only lost 2 series and he was a huge favorite in the 1958 finals.
Jordan kind of went from underdog to favorite very quickly in his career and it shows. With him being a big favorite when he won and a massive underdog when he lost. Also he was 25-0 as a favorite.
Some of it is the Shaq effect obviously, but Kobe comes off looking good by this measure, with 5 titles and not a huge advantage when winning.
Hakeem stands out again for literally being an underdog in his average series victory. Only Jimmy Butler can say that, and he was basically even at -0.09. Oh, and poor Tracy McGrady, whose Spurs series I did not include since he didn't really play.
Fun fact, Lebron played 15 toss-up series where the teams were within 2 points of each other. He went 15-0.