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Tennis Scoreline Probabilities

Tennis Scoreline Probabilities

The Point Value model is all about "Big Points" in a tennis set, or the difference in "value" of different points during a tennis set. The main criteria calculated by the model is the Point Value. Each Point at a partcular scoreline in a set of tennis has a specific value.
    The Point Value is the difference between:
  • your probability of winning the set if you win the current point
  • and your probability of winning the set if you lose the current point
For more information on how to use and interpret the Point Value model, click or tap anywhere within this grey box (tap again to close).
This is an screenshot of the Point Value model in use. The 46th point in the set, a peak, has been clicked on in the graph and is now highlighted in the scoreline table. The score at that point in the set was 4-4, 40-30, and your opponent was serving. You had a "break point" with a Point Value of 40%. Since the point is green in the graph, you won this point and went up a break. A "Big Point" is one that represents a 20%+ swing in your probability of winning the set and these show up as high points or peaks in the graph of the set. The graph shows each point in the order that it was played. Tapping or clicking on a point will navigate the table to, and highlight, that specific scoreline showing you what the score was, what your winning probability was, and what the Point Value for that point was. Green points are points you won. Red points are points you lost.
    You and your Opponent (Opp) are equal in skill and you both have:
  • a serving winning percentage of 65%
  • a returning winning percentage of 35% 
  • These two values are around the average values for WTA/ATP players.
The Your Win Probability column is your probability of winning the set given the current score. Your Opponent (Opp) is assumed to be your equal in skill and therefore the Your Win Probability will be 50% whenever you are tied. The Point Value column reflects how much winning that point shifts your chances of winning the set. It is the change in your probability of winning the set if you win the current point versus if you lose the current point. Very high Point Values, which show up as peaks in the graph, indicate "Big" or Critical Points that can swing a set. Understanding the Point Values at different scorelines can give tennis players an understanding of which points are more important and thereby help them to make smarter tactical decisions. To quickly familiarize yourself with this model we recommend clicking on the Simulate Set button. This will randomly generate all of the points in a tennis set so you can explore the functionality (clicking Start Set and then repeatedly clicking the Random button does the same thing only one point at a time).
The rationale underlying the RoBOPPic's Point Value Model is discussed in detail in the blog post "Playing Tennis like Deep Blue Part 2: Computation and Tennis Tactics."
Tap again on the grey box at the top to hide this background info.

The Point Value table has over 1500 scorelines, all of the possible scorelines in a set of tennis, and each scoreline quantifies the strategic "value" of that particular score in a tennis set. These values are true for any set of tennis you play as long as your opponent is of equal skill.

You can scroll through the Point Value data if you like, but there are three more efficient ways of exploring the Point Value model.

  • Click Start Set and then you can reconstruct, follow along or create a set anew, point-by-point using the Win, Random or Lose buttons to specify who wins each point
  • Click Simulate Set to generate all of the points in a Set of tennis from beginning to end using the random function to determine whether you or your opponent won each point, and then you can examine Your Win Probability and Point Values of the peaks and other points of interest
  • Enter a specific scoreline using the dropdowns and click Find Scoreline to examine Your Win Probability and Point Value for that particular score which will be the same in any set of tennis you play


Enter scoreline to find: