I have had a couple of Hammers crack on me, but AMF and Global crack on me most regular. It's wierd for me...I use Turbo thumbs and when mine crack they start at the thumb. And I say with confidence those that have cracked have been used for a season plus. I don't quite understand.
Never really mattered much to me. Stuff happens. Only real problem is they are usually hand me down balls so there is no warranty.
Heck I even had a Roto Grip Cell (original) crack on me. It went from the thumb all the way back around the back of the ball to the fingers. I was mad, but decided to fix it. I used the clear packaging tape and went all the way around it leaving a small vent hole in the top for air to escape. After I fixed it I reengraved it and went on to use it for 2 more seasons.
It seems more like a seperation between the surface veneer and outer core. Different thermal properties could be causing the materials to seperate creating weak spots is the covers, bam cracks...
