I can't think of any Bigs who didn't play their best ball until their 30's... I've tried looking up a few now. Could you give me a few examples of the many?
Sure, many bigs don't hit their peak until around 30, but here's a few you may have heard of:
Dikembe Mutombo (four best years of his career starting at age 30)
Hakeem Olajuwon (four best years starting at age 30. DPOY at 30 and 31, MVP at 31, Finals MVP at 31 and 32)
Karl Malone (best years at 33 and 34, MVP at 33 and 35)
Marcus Camby (2nd and 3rd best years of his career at 31 and 32)
Rick Smits (best two years at 32 and 31)
Zydrunas Ilgauskas (best year at 30)
Dale Davis (best two years at 32 and 30)
Antonio Davis (best two years at 30 and 32)
Ben Wallace (2nd and 3rd best years at 31 and 30)
Kevin Willis (4 best years at 29, 31, 35, 30)
That's just a small sample. I just checked a few players I knew played their best ball in their early 30s. I'm sure if you check journeyman bigmen, you would find many more. My original quote was many big men don't peak until their late 20s or early 30s. If you include late 20s, there are many, many more (like Shaq, Robert Parrish, David Robinson, Kevin McHale, etc.).
I was just pointing out that Haywood having a career year at 30 is not a rare occurence. I didn't (and don't) intend to compile a list of all bigs who peaked at, or around, the age of 30. Feel free to add to the list.
BNM