Something weird happens when I hit off of a lie board.
When I hit off of a lie board with my irons the tape and lie board show every iron is perfectly in the center (which would indicate the lies are right), but on grass the divots are always slightly toe down (which would indicate I need a more upright lie).
Another discrepancy:
My normal ball flight is a draw and most misses are left (which is the opposite of what too flat a lie should produce).
My favorite surface on the course to hit off of is baked out hard pan clay (or very short grass on hard ground). Off of a hard surface I can hit consistently good shots time after time. The softer the ground, and the more the ball is suspended above the ground on the fairway grass, the more inconsistent I am.