Originally Posted by cbwheeler

Here is what is happening. When you have a longer club in your hand, you subconsciously want to swing it harder. This is something we as golfers all fight against. It happens to absolutely everyone. Most golfers, when they swing harder, do it with their arms which causing a casting effect that results in an open clubface and a glancing blow that causes a slice.

The solution? Head to the range and choke down about 3/4 of an inch on your 4 iron to groove the feel of hitting it nice and smooth. This will help to control it and will build your confidence. This will also help to instill in your mind that a 4 iron can be swung smoothly and still fly the same distance.

Once you've got it down, gradually go back to normal length. Honestly if you want to, you can leave it choked down. You'll notice a lot of tour players choke down on their irons quite a bit, Sergio Garcia being one of them, one of the world's best ball strikers (although a head case of a short game).