Golf clubs are notorious for actually moving irons down the numbers to fool you into thinking brand new clubs are so much better. You go to a shop and hit your 6 iron on the golf simulator, then you hit a brand new 6 iron and see you hit it further, then you buy the new club thinking all your shots will go farther thanks to modern technology. What you don't realize is that what is called a 6 iron in your new set actually has the exact same specs as your old 4 iron, and might not really go any farther at all when you compare it to your old 4 iron.

It's the age old trap of selling beginners gear instead of practice (which makes manufacturers nothing).