Maple is a very hard, dense wood. The surface hardness is about 20% greater than ash. The harder the surface, the faster the ball will jump off the bat. This is one of the reasons maple has become so popular. Maple is a closer grained hard wood than ash. The grain is not as easy to see as it is with ash. Maple will not splinter. The grain will not separate. The hardness of maple makes a bat with less flex.
Ash on the other hand does flex. When a ball is hit with an ash bat, there is a trampoline effect. The ball doesn’t just jump off; it first compresses the wood, then like a spring board it leaves with much more force than maple. This spring board effect is one of ash’s greatest strengths and weaknesses. The spring board and compression traits of an ash bat will cause the grains to separate over time. The flex of an ash bat will appear to have a larger sweet spot. Ash bats do not snap the way a maple bat does. Ash bats will break just as easy, but usually they just wear out. The grain of an ash bat will delaminate over many uses.
Birch is a great mixture of both maple and ash. it is great for first-time wood bat swingers, closer in strength to hard maple, falls between maple and ash for wood density, good protection against inside pitches and you still get some of the flex of an ash wood bat. Birch should be a strong consideration for any player but especially the player new to the wood bat world.