this is a classic teaching concepts that is as out-dated as the linear FH, but is not talked about much, perhaps due to the 1hbh being less popular. unfortunately seems this method is still being widely taught. in the days of 65in wood and 85in graphite, staying sideways and hit thru the ball makes sense, to avoid shanks. today's equipment changed the FH, and it changes the 1hbh in a very similar way... players now hit across the ball.. wawrinka, schiavone, dimitrov, gasquet, fed... they all open up thru impact to hit across what does this mean exactly - 1) the backswing does not need to be as deep as the old method... similar to open stance FH has a shallower back turn 2) upper arm connected to the chest during the foward swing, makes timing easier, ensure solid contact. 3), chest angle can be varied - facing more towards the sky to handle high balls, facing more towards the ground for low ones. 4), the swing path now makes it possible to add forearm motion to further increase spin.