I have bought well over 250 ball from 900Global and still have a ton  new in box with no issues what so ever on the new or old 1's and have only had a hand full crack on me over the last 7years. Ive have had only 1 crack on me with out even drilling it    have had the Bounty solid a Pure Hook (the Pure Hook cracked less then a month ago and was never replaced by 900global for only being 5-6 months old if that but have others replaced with in a year of release date ) also the War eagle and a Train crack starting off  from the thumb hole cracking no less then 6". my bank of 900 pearl cracked starting off the ring finger going 4".  Maybe it has something to do with where you are keeping them when your not using them or they are getting to hot or to cold.  Its not very normal for a bowling ball to crack just because.. I feel for you when one does crack, Don't feel like its only happening to you because it's not. I doubt many have had that many crack on them over the years as you have .. sorry to hear your not going to throw them any more. good luck with your next brand.