The first aspect to consider is club-head speed. You need lots of it to get the ball high in the air with a long iron. As a general rule, a golfer needs to be able to hit the driver at least 225 yards in the air to make use of a 4-iron. To use a 3-iron, the golfer should be able to move the driver out to some 260 yards. Swings of lesser speeds won’t impart enough backspin to get the ball flying high.
Hybrids, constructed with more weight in the sole of the club, are much easier to hit high in the air. The benefits of this are two-fold:
First, it allows the golfer to hit towering long shots that stop quickly on the green. (This is more difficult to do with a long iron that both sends the ball lower and with less backspin for stopping power.)
Second, when the average golfer looks down to see the tiny head of a 3-iron nestled tightly behind the ball, tension can mount. A nervous golfer is not likely to swing the club at a manageable pace. Hybrids, on the other hand, look much more suited for the task, promoting a confident, more relaxed swing and therefore are more likely to get the job done.
Unfortunately, for those who are a bit unsure as to which hybrid replaces which iron, there is no set rule. Some players say their 5-hybrid replaces their 3-iron while the guy next to him might say he uses his 4-hybrid instead of his 4-iron. The key is to experiment, to determine which clubs you need for your game.
As for the player with higher swing speeds, I would still recommend you to ty to find use for at least one hybrid in your bag: for instance a driver, 3-wood, and either a 3-or 4-hybrid. You might also take a peek into the bags of the best players in the world. You’ll find that they too are making great use of hybrids in places where they once hit a long iron.
Hopefully you’ll take the time to find the clubs that best suit your game. It is one of the few changes you can make that will immediately improve your scoring.