needs 1 more ball for his 2 ball arsenal. Something that can handle medium/heavy without to much of a gap from the QZ2. He bowls high school and recently went up to 13lbs. Basically bowled on a house shot, but bowled in the city tournament and had to play down and in which is not his "A" game. Still qualified 9th (not bad for a freshman) but wish he had a stronger ball. Help needed for I'm not familiar with Motiv equipment.

Thanks...9

Since the QZ2 is a medium-light ball, I'd probably lean towards the Sigma Hybrid.  This will easily handle larger volumes of oil and work best on medium and medium-heavy patterns.  Plus with having the hybrid cover/core combo seen here, it's very smooth and can help blend out conditions to score better.  This would allow your son to move inside which you mention is his "A" game.  But if he needs to play outside, it's very usable there too.

Basically you'll get higher end performance for a midrange price here.  At the same time, the Sigma Hybrid is really versatile and can be used on a wide range of conditions.  Going higher into their Raptor line, Primal Scream or 2Cruel may be a bit overkill for the time being.

Thanks for your responses. I'm leaning towards a Primal Scream or Sigma Hybrid. I don't want to over complicate things for him, so I'll skip the medium ball for now (Thrash, Sigma Tour). He throws the ball really well for 14yr old who hasn't bowled in 2 yrs. I'll try and post a video of him this week......9

If it was me, I'd opt for a (strong middle road not maximum) the Sigma Tour which is a strong ball by any standards but more usable (low Rg and .045) on tougher patterns than many.   It definitely has enough strength.  The Primal Scream if you are looking for length and a lot of backend is fine but that's not where you put a younger bowler.  Hard for many novices to read the lane condition and backend and make the moves necessary to stay in the pocket.  The Venom Strike (low Rg .031) control ball but more strenth than the numbers tell.....would be slightly under the Sigma Tour.  ST is more ball than many are thinking. 

Look at the bowlers stats. and lane condition faced then make the correct choice.  Pro shop operator should be able to help make those choices after he measures for PAP and other stats.

BTW...../the Sigma Tour is the black ball right in the middle of the Motiv ball guide.  The Sigma Hybrid is red.  Ball guide should help but not the end all to be all.  For instance I don't use my 2 Cruel on house shots and when I use my Primal Scream it's always deeper inside on house shots.  Do you really want to put a say a more down and in bowler in a situation they are not accustomed to playing?  It can be a good learning situation but also can be very frustrating.  http://www.motivbowling.com/resources/finishes.html