Rescue clubs exploded in popularity amongst professionals and amateurs because they are easier to hit than long irons or fairway woods.
 
The secret to their success lies in how the clubs are constructed. The cavity on the back of rescue clubs is deeper and wider. This means manufacturers are freed up to move weight to the club head perimeter. Moving the weight to the perimeter of the club creates a high moment of inertia (MOI) at impact. MOI is the amount a club twists at impact. Clubs with a higher MOI twist less and give more distance on off center hits. Long irons, especially bladed clubs have lower MOI with means they twist more on off center hits and are less forgiving.
 
The hybrid or rescue clubs are a combination of long iron and fairway wood (hybrid) and extremely adaptable from poor lies (rescue).
 
This hybrid design can be seen in the wide, smooth sole of rescue clubs. The sole shape and deep center of gravity helps lift balls from poor lies including deep rough and even sand.
 
How to hit a rescue club
 
Because hybrids are a combination of long iron and fairway wood, the set up and strike should also be a combination of long iron and fairway wood.
 
The first thing to establish is the rescue club’s loft. For example, if the rescue club has the loft of a long iron like a 3 iron, players should set up as though they were playing a long iron shot. Most rescue clubs generally have a loft similar to long irons as these are generally the most difficult clubs to hit, although hybrids go as low at 15 degrees and as high as short iron lofts. Below is a guide of how to set up and hit a rescue club with a 3 iron equivalent loft (22 degrees).
 

• The ball should be placed forward of center in the stance, a few inches inside the left heel (for a right handed golfer).
• The feet, hips and shoulders are set square to the ball-to-target line, presuming the golfer wishes to hit a straight shot.
• Because of the length and sole design, players need to meet the ball with a very slight descending arc. Rather than sweeping the ball away off the surface like a fairway wood, players should be bruising the ground just after the ball.