The game of tennis has evolved over the years. As tennis entered the open era, a modern style of baseline, topspin hitting was used more often. This change opposed the traditional slice and flat hitting style of the early pros. As the game changed, more extreme forehand and backhand grips were developed. 

Federer Forehand
Credit: http://www.zimbio.com/pictures/tKgHvIrVOSf/Championship+Wimbledon+2009+Day+Thirteen/wKSPohDgYUC/Roger+Federer

Forehand Grips

There are three forehand grips that are mainly used in the modern game. These grips allow the players to hit topspin more naturally. These are the forehand grips that are most commonly used by the modern professional and recreational player.

  • Continental Grip
  • Eastern Grip
  • Semi-Western Grip
  • Western Grip

Continental Grip

The continental grip is known as the most versatile grip in tennis. This grip can be used for the serve, volley, forehand, and backhand. The continental grip is not a widely used forehand grip. This is mainly because of the inability for the player to hit topspin with ease. In order to hit topspin with the continental forehand grip, the player has to pronate (flex) his wrist and swing in an exaggerated upward motion. The contact point of the continental forehand is low and is therefore uncomfortable for many players to hit a high forehand. Players can obtain the continental grip by gripping the racquet as if it were a hammer or an axe. The continental forehand is sometimes known as the "chopper grip." Many of the old professionals like John McEnroe used this grip to great effect for serve and volley tactics. 

John McEnroe Hits Continental Forehand
Credit: http://upload.wikimedia.org/wikipedia

Eastern Grip

The eastern grip is the forehand grip that most closely resembles the "old" continental grip that all the previous generation professionals used. The easiest way to obtain this grip is by holding the racquet perpendicularly so that the frame of the racquet is facing up, and the strings are facing outwards. After the racquet is perpendicular, the player should grab the racquet like they are shaking its imaginary hand. By using the eastern grip, the player can hit more natural topspin. Not many modern professionals use this forehand grip because, although it is versatile, the hitting zone of the eastern forehand is uncomfortably low for the modern topspin game. This grip allows the player to hit more topspin while still retaining the abilities of the continental grip to "hit-through" the ball more.

Eastern Grip(94590)
Credit: http://www.tennisserver.com/turbo/turbo_03_06.html

Semi-Western Grip

The semi-western grip is the most commonly used forehand grip in the modern era of tennis. It is a perfect in-between for the players looking for a "spinny" forehand and a more powerful shot. Most of the professionals on tour use the semi-western grip because of the balance and versatility that the grip provides on court. In order to obtain the semi-western grip, the index knuckle of the dominant had has to be placed on the bevel (ridge) of the racquet handle that is one above the bottom ridge. The semi-western forehand is ideal for many players because of the contact point of the forehand. The contact point is in front of the body, and the shot can be hit anywhere between the hip and shoulder of the player. This allows players to hit balls that bounce higher up because of the topspin. Unlike the continental and eastern forehand grip, the semi-western grip requires little pronating of the wrist. The versatility of the semi-western grip is what makes it the most popular grip on the ATP and WTA professional tennis tours. 

Tsonga Forehand
Credit: http://www.tennisnow.com/Files/Teaser-Images/Tsonga-Forehand-AO.aspx

Western Grip

The western grip is the most extreme out of the forehand grips. This grip allows the player to have the most spin potential on the ball. It is a popular grip on the pro tour because the contact point of the western forehand is in front of the body and shoulder height. This allows the player to handle heavier balls that kick up high. The western grip can be obtained by putting the dominant hand's index knuckle on the lower-most bevel on the handle. The western grip forces the grip to pronate more, which puts more natural topspin on the ball. Although there is more spin, some players have a harder time hitting through the ball since the wrist is pronated so much. This causes less power in the ball, but more spin. The western grip is not as versatile as the eastern or semi-western grip, but it is popular among the modern baseline bashers that are prevalent in the game today.

Nadal Forehand(94596)
Credit: http://tennisseven.files.wordpress.com/2010/05/img2145563981.jpg

What Forehand Grip Should You Use?

There are only a few people who still use the continental forehand grip. The continental forehand grip is the least useful in the modern game of tennis because it is harder to handle high balls because of the continental's low contact point. Although the eastern forehand can handle heavier balls better, many players walk away from it because of the difficulty of pronating the wrist on balls that bounce higher. The semi-western grip is the most ideal from the "weekend-warrior" to the rising professional. The western grip matches the powerful, baseline bashers who are numerous in the game today. The difficulty of the western grip is generating pace and handling low balls. 

The more western the grip gets; the more spin potential is possible with the grip. The grip that feels the most comfortable is the one the player should use. 

A good video that demonstrates the differences between the grips is the Australian Open 2009 Men's Final between Roger Federer and Rafael Nadal. Federer uses a grip that closely resembles an eastern grip, while Nadal uses the modern western grip.