I don't think any starting-quality NBA players "fold" under pressure. I do think a number of them perform slightly less well. It's easiest to see in FT%, since it's the same shot with no defender. Some guys (Kevin Garnett, Steve Nash, Robert Horry, Michael Jordan, Drexler, Ben Wallace) see minuscule differences in their FT% between regular season and playoffs. Some see greater: Player: Career RegSeason/Playoffs Shaq: .527/.505 Reggie Miller: .933/.893 Kobe Bryant: .838/.815 Trevor Ariza: .658/.542 Mo Williams: .869/.787 Lamar Odom: .701/.638 Cliff Robinson: .722/.636 Rick Fox, James Posey and Dikembe Mutombo did see slight increases in their FT% in the playoffs, though. Maybe the small falloff in some of those players (Kobe, Reggie) might be due to fatigue of playing a ton of minutes. But I think there are also definitely players in the league who are more prone to getting rattled under pressure than others.
The list has players like Reggie Miller and Kobe Bryant who are hailed as premier "clutch" players in NBA history. Doesn't that randomness in who shows up give you pause? I mean, you can always explain away the results that don't fit the theory (like saying maybe they were just fatigued), but IMO the better default is that it's random fluctuation. If you take any arbitrary split (for example, free throws on Tuesday nights), you will find a list of people who are above their career norms and players who are below their career norms. I don't think Kobe and Miller get "rattled" under pressure. Nor do I think Shaq does or Ariza or Williams.
I guess we just disagree. I've seen guys in games look like they absolutely hate the idea of having to step up to the line. Shaq is an absolute classic. There are games I've seen where he clearly seemed to be rattled. It's not everybody. In fact, I suspect the majority of NBA players aren't really affected by pressure. But I think there are also guys (like Shaq) who have such an immense talent in some areas that they can get buy with sub-par mental toughness.
Hmm, that's strange. I had a different impression. I had the sense that he usually didn't give a shit at the line, but when he started getting hacked at the ends of games that mattered, he got pissed and wanted to take the free throws. I also remember him saying "I make the ones that matter" (not true, but also not suggesting a lack of confidence under pressure) and I remember a few Lakers fan friends of mine in the early 2000s saying "Kobe is money at the line the first three quarters and misses in the fourth quarter. Shaq misses them in the first three quarters and gets better in the fourth quarter." Not that either of those things have much to do with reality, but it just shows (me, at least) that I wasn't alone in my impression about Shaq and free throws.
I always got the impression that he pretended not to care, but it bothered him underneath. There's just something in his body language that always said to me, "Let's just get this free throw stuff over with as quickly as possible so I can go back to being a great basketball player." I really think he's always been kind of embarrassed about it. If I were him, I know I would be.
Williams is weaker than Bayless, or even Koponen, so I hope this "rumor" is nonsense. If KP is even considering Williams, we need a new GM.