The Tour X is another new release from Track. It doesn't quite go along with the new naming system, but this ball is a must have for tournament bowlers and for sport shot league bowlers. First thing that stood out to me about this ball is the core.. This release features the "DNA" core that was featured in the 300C Solid and the 400ASE. This core is a symmetric core and by nature, not as dynamic as some of the others we have released. That means that the ball will be much more responsive to surface changes made, which as a tournament bowler, I really love. If i need a little earlier hook I can dull it down with a rougher abralon pad, or i can bring the surface up and polish it if I need it go get through the front a bit easier. Now for the cover, this ball features a brand new version of the cover that was on the 400ASE. This new cover is call the "Luxury DR-4 Pearl" cover. This cover, in my humble opinion, is one of the most versatile coverstocks we have ever come out with. It was designed for medium to light oil, and for tougher sport patterns because with how clean this ball is through the front, it never really jerks hard out of the pattern.. it really is very smooth and controllable down the lane which makes it ideal for those tougher patterns where a large change of direction can get you into trouble. This is the ball that EVERY tournament bowler and sport shot league bowler needs to have in their bag. Make sure to check out Trackbowling.com for the Tour X and more.. "When the lanes get tough, smart bowlers get Tour X"