The amount of base bevel will determine how much the board will be allowed to transition from edge to edge before the edge actually engages into the snow surface. Here is an example..downhill racers will have a good degree of base bevel, often at least 1.5 degrees plus. This will allow the ski to roll higher or become more perpendicular to the snow surface before it truly engages. As the disclipline gets to the point where turns become closer and tighter , happening more often, the desired base bevel becomes smaller. many slalom racers who are making turns within close proximity will use base bevels of .5 or .7. Most will not notice the difference between a .5, .7 or even a one degree base bevel. Its accuracy can be noticed when the surfaces are ice, any thing short of that it becomes hard to tell. All boards or i should say most that come off of a gring will have some degree of base bevel...reason being is that if the operator knows what he is doing, will put some in so the edges dont wreck havoc on the stone. Accurate bevelsare then put in after the grind.