Sorry if my title confused you. What I meant was that I see many right-handed professional players, with the exception of Taufik, electing to hit a cleared shuttlecock with a forehand rather than a backhand even though the shuttlecock is very far to the left. I always thought professional players would have the backhand strength to clear or smash the shuttlecock with ease, rather than relying on their forehand and sacrifice their positioning. Is Taufik one of the few pros who are confident enough with their backhand to not hit a backhand shot with a forehand? Are there any strategic reasons to hitting a shuttlecock cleared to one's weak side with one's forehand?
Put very simply an around-the-head shot gives advantages of power, control and placement. And, very importantly, a backhand puts you facing away from the play.....you can't see well, and you are not in postition to move quickly around the court.
Yeah, no matter how good your backhand is (unless you're Taufik), your round the head forehand is almost certainly better. The comment about facing away is a big one - the professional game is fast, every millisecond counts. If you hit a backhand clear down the line, you'd have a long way to move if your opponent responded with a drop to the opposite corner. The time it took to turn back from hitting the backhand could play a big part in whether you got to that shuttle.
Hitting forehand will also allow you see where your opponent is moving so you can place a well position shot.
The body action/rotation/scissor kick of a round the head shot also brings the players recovery back into a base position to cover the most dangerous replies. With a backhand the dynamic movement is less towards a recovery back to base.
There's actually probably more deception with the backhand since the preparation is covered up by your body....however the recovery is worse since you are more rooted in the position and will be unable to "spring" back into a good ready position. Also, using the forehand lets you strike with more precision, power, and in general is better, except it requires more speed and stamina.
The advantages of the forehand are that you can hit with more power and control, and most people find it easier to learn I think. The obvious big advantage of a backhand over a round-the-head forehand, is that you have to move less and can reach further - there are times when you just physically can't hit a forehand. Unfortunately, a lot of players with good backhands get lazy and try to use it as a substitute for good footwork, which ultimately weakens their overall game. Personally, I have to use forehands for all overheads, due to numerous long-standing thumb injuries (don't ski or play rugby if you want a future in badminton), and it can be a weakness sometimes. I think it's definitely good to have both shots in your repertoire if you can.