In the early 1990's Bill Jacobsen came out with the concept of the Aggressive Margin and it has been a cornerstone of interpreting matches ever since.
Two key statistics that are required to really understand match outcomes: the Forced Error and the Aggressive Margin.
A Forced Error is an error that stems from pressure created by the other player’s ball. This is different from the more familiar concept of the Unforced Error. An Unforced Error is a mistake that a player makes on an easy or routine ball—the error stems from the player’s inability to execute what should be a simple stroke or return.
A player generates a Forced Error through pace or location, or a combination of both, say for example, a deep, high velocity crosscourt forehand. The other player reaches the ball on the run and takes something resembling a normal swing, but is unable to control the ball and return it into the court. Even though the player had a chance to make a return, the error was “forced” by the opponent’s aggressive play.
Forced Errors are critical statistics because they account for up to half or more of the points in most matches.
The Aggressive Margin
So tracking Forced Errors is critical. Once we start to track Forced Errors we can then combine them with the better known stats of Winners and Unforced Errors to calculate the second key stat, what is called the Aggressive Margin.
The Aggressive Margin is the total of a player’s Winners and Forced Errors minus his Unforced Errors.
For example, let’s say a player hits 10 Winners and generates another 10 Forced Errors. That’s plus 20. Let’s say he makes 10 Unforced Errors, that’s –10. Subtract the Unforced Errors from the Winners and Forced Errors (20-10 = 10.). That’s an Aggressive Margin of +10.
The Aggressive Margin gives us an instant understanding of how a given match was really won or lost. The Aggressive Margin can be a positive or a negative number. It shows whether a player is playing positive tennis, or simply relying on his opponent to make more errors than he.
The Aggressive Margin is not an absolute. It’s a relative measure that reflects the quality of the points and shotmaking between particular players at a particular level in a particular match.
This basic principle of positive percentage tennis seems to be virtually universal among successful players at all level. They understand their shot making capabilities and use them to set up and execute winning point patterns.
Statistical tennis is the key to victory. The best players will win more points than they lose by playing correct patterns and making high percentage shot execution.
Tourmament or Match Level Aggressive Margin
Winner Aggressive Margin
Loser
Sampras/Agassi + 25 +20
Top juniors + 10 +5 to neutral
Developing the ability to win points through positive shot making is the key to winning—and making sure you’re positive shot making exceeds your unforced errors.
Unless you can play positive statistical tennis on a consistent basis, your only hope is that your opponent has worse negative numbers than you. This explains why some players win one match, think they are playing great, and then are mystified when they play exactly the same way against another opponent and lose badly.
Basic Patterns: for the 4 basic gamestyles - aggressive baseliner, counter puncher, all court player, net rusher.
Serve:
Serve wide
Serve into the body
Serve down the middle
Return Patterns:
Neutralizing your opponent
Deep cross court
Attack down the line / Chip and charge
Approaching patterns:
Approach down the line
Approach up the middle
Force and follow
Approaching from the middle (crosscourt or inside out)
Serve and volley
Return chip and charge / rip and roll
Move opp around then approach
Sneak in after drop shot / heavy ball
Baseline patterns:
Rally crosscourt
Hit a side T
Inside out forehand
Cross court then attack down the line off short ball
High balls to backhand
Deep, then low and short
Patterns utilizing your forehand as a weapon:
Serve position and recovery
Return running around backhand
Imposing hi fh tempo
Running around bh
Heavy ball then drive
Getting into the fh diagonal
Opening up the crt
Modifying your position
Patterns to make your opponent move:
Serving wide
Return away from the middle
Taking control of the middle hitting targets 3/4/5/6
Hitting diagonal side T
Changing directions
X pattern
Drop shot / underspin short and low
Open crt volley
Wrong footing shot
CONTROLLING MOMENTUM
At the beginning levels of strategy, game plans tend to focus on (1) shot selection and (2) patterns to use against opponents, such as where to serve, where to hit ground strokes and which of the opponent’s strokes are vulnerable to attack.
After these strategies are learned, the next step is to manage the flow of the match by applying momentum control guidelines. Professionals are experts at managing momentum. Tennis, more than any other sport, is a game of momentum. The absence of a clock to do the dirty work of finishing off an opponent, and the scoring system, makes the flow of the match of utmost importance.
In other sports, momentum can sometimes be controlled. Basketball coaches are perhaps the most adept at shutting down “Mo”. They have their players pressure the opponents at times and back off at other times, hoping to frustrate their opponents into making mistakes. All too often in tennis, strategy is planned around an opponent’s weakness, and match tempo is dictated by how a player is feeling. This would be absurd in any other sport, yet in tennis even the best players go into matches with the assumption that the outcome rests on their technical skills alone.
Many aspects of momentum can be controlled, however. These are based on three variables in the match, as follows:
1. The conversion principle - The grouping of points
2. Action-reaction principle - The action taken when good shots and bad shots are made by you and your opponent
3. Momentum principles based on the score - How the score affects the pressures
The sequence in learning and controlling momentum and match flow should be as followed.
The basic tools with which you have to work are quick-pressure tactics and delayed-pressure tactics. A quick, aggressive point forces your opponent to react immediately, whereas delayed pressure sets up the point more methodically. Quick-pressure points are also referred to as a “mo switch” and delayed-pressure points are referred to as break-down points.
1. Conversion principles
To make a conversion means to win three points in a row.
Your first objective in controlling momentum is to make conversions and to prevent your opponent from doing so. Usually the best way to accomplish this to recognize all two-point sequences won and lost and focus intently on the third point.
Remember this motto: Three in a row starts a flow.
2. Action-reaction principles
Four actions can cause a reaction that is positive or negative when a point is played:
A great shot by your opponent. You should use quick pressure tactics to win the point back immediately, negating your opponent’s momentum potential. (If they give you a whack, hurt them right back.)
A bad error by your opponent. Apply quick pressure to immediately increase the tempo of the points and to take the upper hand when your opponent is unsettled. (If they make a careless mistake, a quick point try to take.)
A great shot by you. Return to your fundamentals while maintaining an aggressive posture. Usually, a delayed pressure point should be played, but without playing tentatively. Tempo between points can be increased, but points should never be rushed. Quick targets should not be given to your opponent. If your shot has hurt them and they’ve started to bleed, delayed pressure to fester the wound is all you need.)
Note: If your opponent reacts aggressively with success, follow the same guidelines and then return to delayed pressure tactics.
A bad shot by you. Take your time to regroup and return to the style and fundamentals in which you have confidence. (If you bad shot has you in a fret, keep your poise, stick with fundamentals, and don’t start until you’re set.)
If a point has been played where no momentum from action-reaction guidelines has taken place, use the following momentum guidelines based on score.
3. Momentum guidelines based on the score
It is a general principle of competition that an individual plays better and hits more aggressive shots when he or she is behind, and makes more mistakes by being tentative or rushing when ahead. This applies to games, sets and matches.
Most players tend to do only as much as they have to do to manage a situation, but good competitors play their best when their back is to the wall. Therefore, you should know how to use delayed-pressure tactics (breakdown points) and quick-pressure tactics (momentum-switch points).
To manage momentum swings that are caused by this changing pressure, observe the following rules:
- When you’re ahead: Play smart and continue to apply steady pressure.
- When you’re behind: Play aggressive with more quick pressure tactics.
- When you’re even: Go with your favorite style and have it locked in by the end of the match.
Other factors can affect the momentum of a match as well. Some can be controlled, others cannot. It’s important to be aware of them and know how to deal with them.
You should be aware of the following momentum changing and flow reversing factors:
- When a player has just won/lost a set.
- When opportunities to win games are not converted, especially large leads of two or three points.
- When a player has just won/lost a very long game.
- Rain delays
- Injury timeouts
- Bad calls by your opponent or by a linesman
- Emotional disruption by an opponent that may or may not cause a code violation.
- Code violations
- Equipment changes
To counter these obstacles, or take advantage of them, you must first be aware of the situation and then run the proper plays following momentum guidelines.
Momentum is the most powerful force in sport. The more aware of it that you are, the more control you will have over the outcome of a match and the less prone you will be to a breakdown during a match