fungo,
from learning what to look for in the wood, here's my 2 cents of knowledge...
1.grain should be as straight as possible.
every now & then you'll see a wave or ripple in the grain... this will be a weakspot, so beware.
2. grain should be wider layer & evenly spaced. This indicates to me that the tree has grown equally from year to year.
3. when hitting, label up, perpendicular to line of the ball meeting the bat.
My son is credited for my knowledge... Someone Very wise must have told him.
Or... maybe he just "lucked out" with this bat!
Anyway, it has been a "good 'un"
Maple is a hard wood, ash soft...now, that I know is fact!!
One last thing... He won't buy a "painted" bat... Natural stain or cherry stain only...so he can see the grain (and maybe a "luck" thing, too.