James has 45.8 Playoff Win Shares. One other player is within 30% of that figure -- Tim Duncan (32.9). If you even say "who has HALF of LeBron's Playoff WS?" you get Duncan, Kobe and Dirk.
Well, LeBron has played a long time, so he has an advantage. What if we go with WS/48 and give the young stars a chance? Of guys who have logged 2,000 playoff minutes, NO ONE comes within 10% of the playing level of LeBron. And only three guys play at even 90% of his playoff level
Kawhi Leonard, Chris Paul, Stephen Curry.
Guys who have not played at even 60% of LeBron's playoff level despite far fewer minutes? Ray Allen, Steve Nash, Paul Pierce, Jason Kidd.
Don't care for Advanced Stats?
Minutes Played - LeBron
Baskets Made - LeBron (400+ more than 2nd place Duncan)
Rebounds - Duncan, then LeBron (+468 on 3rd place Ben Wallace)
Assists -- LeBron (+390 on 2nd place Jason Kidd)
Steals - LeBron (+104 on Ginobili)
Points -- LeBron (+1,316 on Kobe)
The reason that LeBron James is always compared to players of the past (Jordan, Kareem, Wilt) is that he simply has no fair comparison against players of his own era. If you are an excellent player and have played in the 21st Century, it is your HOPE that you have been 80-85% of the player that LeBron James has been. If so, you are an excellent player of the Century, you might be 20-45% less productive than LeBron James.
And he is STILL better than you (#ESPNRANK ranks James as the #1 NBA player again this year).
Look at playoff wins this century
No one else has 100 playoff wins. Only ONE of James' teammates (Wade for 4 years) has 100 wins, and he has 40 fewer than LeBron. Duncan, Parker and Ginobili all played together. Most of Fisher's and Kobe's wins came playing together. LeBron carried guys for several years in Cleveland - who never again did anything, then he carried Wade for 4 years in Miami - who has never since done anything, and now he has carried guys in Cleveland (Kyrie, Love, Delly, Tristan) who have never done anything in (or even reached) the playoffs without him.
Is it conceivable that Kawhi Leonard or Kevin Durant could go on a 6-9 year tear and surpass LeBron? Possible, But neither has even 20 WS. LeBron is likely to end with around 50-60 WS and a WS/48 around .22-.24. That means Kawho and Durant would need to have around 9seasons of 4+ WS at a rate of .300 WS/48 to match LeBron.
There has only been ONE such playoff season in the past 17 years - by LeBron.
If you assume that you could play 9 years and get 4 WS per playoff year and play at a rate of .241 WS/48 and eventually come CLOSE to the stats of a declining LeBron (not true, but assume that), since 2000-01 there have been 10 such seasons. LeBron has 6 of them (Duncan, Manu, Howard, Dirk).
The 21st Century has been dominated by LeBron James. It is likely that the next guy who matches his production has not appeared in the NBA as of today.