Golf Swing vs. Baseball Swing?

I was at the driving range today and am right now watching the baseball World Series, and the following occurred to me;

Why is it that in golf it is of paramount importance to keep the left arm straight, while in baseball the left arm is bent? (That’s for righties, and the opposite for lefties.)

Yes there are differences in the requirements - the golf ball is on the ground and stationary, while the baseball is about at waist level traveling past you, and the club is longer than the bat. But there are also many similarities. I have even seen golf instruction videos pointing out important steps in the golf swing and noting “just like a baseball swing”.

So why can’t a successful golf swing employ a bent left arm? Or for that matter a baseball swing with a straight left arm?

Because during a golf swing you want to be at full extension when you address the ball - if you need to bend your arm, it means the ball is too close in your stance.

During a baseball swing, you have no idea where the ball will be, and you can’t move your feet to ensure you’re at full extension when you hit it.

I’m a very bad golfer, so take this with a large container of salt.

I believe that the act of straightening your arm (which will happen if your arm is bent) will cause the face of the club to strike the ball while moving laterally toward you, putting side spin on the ball, resulting in a slice. A straight arm will keep the face moving straight forward. Not something you need to worry about with a baseball swing.

You can bend your left arm in a golf swing, however it should return to full extension at the hitting position. If it doesn’t you’ll lose too much power.

Modern teaching for the last 70 years pretty much all agree that if you want extension at the hitting position, then you should start with the left arm extended and keep it that way throughout the swing. Then there’s one less compensation to worry about as you get into the best hitting position later.

The baseball swing has a target that moving in three dimensions - your stance and arm positions should be flexible enough to allow milli-second compensations that are required to get the bat to meet the moving ball.

I’m guessing if you saw a slo-mo of a batter hitting a powerful shot, his arms would be extended.

Baseball bat is round.

A club face is flat.

Baseball is in different locations when being hit.

A golf ball is stationary when being hit.

A batter has a much broader target from left foul line to right foul line.

A golfer has a fairway or green to hit.

The biggest factor is the round bat, as compared to the flat surface fo the club head. Rotating it around the long axis doesn’t change how you hit the ball. Rotating a golf club, however, changes everything.

For comparison, what’s a cricket stance look like?

I think this is only true at the quantum level.

I’m no expert on cricket, but my understanding is that the ball can be just about anywhere. You have to be prepared to hit it in the air, on the ground, on a short hop, and you can hit it in any direction, even straight back behind you. In addition, you are protecting the wicket, somewhat like a goalkeeper.

Here’s one picture of a batsman addressing a ball –

It is generally true in baseball that the more powerful hits will occur when the batter gets full extension of the arms. Since the ball’s location is different from swing to swing it is not always possible for the hitter to achieve maximum extension (straight front arm). In golf the ball is always in the same place relative to the golfer, so you can ensure maximum extension by keeping the front arm straight.

Here is an article that discusses baseball swing mechanics and includes an image of a maximum-extension baseball swing:

There is no real requirement of any kind for a golf swing. A consistent swing, even if it has several mutually correcting variables, can be quite effective. Obviously a simpler swing is easier to keep consistent…

There are a handful of varations on a standardized approach (including a straightened left arm) because such an approach has a history of being successful when used by very good golfers. A straightened left arm helps keep the arms extended and tends to add power (imagine yourself pounding for the cigar at the fair and how you get more power with a fuller arc), but it’s not a requirement, even for a successful swing.

FWIW you might want to look one of the GolfDigest’s September articles (the issue with Justin Timberlake on the cover). It has a couple pros giving each other tips and addresses your exact issue. I don’t have it in front of me but I remember one guy tended to collapse his elbow at full address, and there was a discussion around how it reduces power, although it may actually improve accuracy.

To the best of my recollection there aren’t very many current golf pros who do not use a fully extended left arm on the backswing. In years past there were and many older videos show surprisingly fluid backswings.

Of baseball I know nothing, having never seen a game–amateur or professional.

There are several stages in a baseball swing (stance, load/trigger, stride, swing, contact, extension, follow-through). The extension occurs after contact. It can occur at contact but there are several variables so timing would be difficult. Here is a good photo just before contact, left elbow still bent and will be at contact.

Here’s another onebut it’s a little leaguer instead of a pro. I took it but I don’t know if the ball is on the way in or out in this shot. This is the classic swing that is generally taught at the instructional level.

“Hello, ball!”