# Dynamic Win Probability

1/3 = 100%

This equation may not seem correct. It isn’t correct to a mathematician but for high-level tennis players it most certainly is accurate.

Tennis has unique scoring. Even if you win more points or more games you may not win the match. Scoring isn’t cumulative for the entire contest like most sports. Every point is not created equal. Therefore, it’s not just how many points you win but which points you win that usually separates winning and losing. Having the right mindset before you start your point is critical to success in tennis. This match charting shows the win probability as a game goes on. Just like the Patriots in Super Bowl LI against the Atlanta Falcons where their win probability fluctuated throughout the game and was anything but certain until the last play of the game, with the Pats winning 34-28. Tennis is the same way. When you are up, do what you did that got you there or put another way, “dance with the person who brought you to the dance.”

If you are up 40-LOVE, then all you need to do is win 33% of the remaining points or one of the next three points and you will win the game 100% of the time. Likewise, when you’re up 40-15, then you just need to win 50% or one of the next two points to win the game 100% of the time. If you are at 40-30 then you need to win two of the next three points or 67% of the remaining points to win the game 100% of the time. And finally, when you are at deuce, you need to also win two of the next three points or 67% of the remaining points to win the game 100% of the time. This does not take into account the ability level of both players or teams nor does it consider a player’s particular strengths (either front-runners or players who play solid when down). But the importance in understanding this foundation fact for tennis scoring lies in your mindset approach to playing the point. For example, at 40-LOVE, going for an ace is overkill and quite frankly and unnecessary risk, contrary to popular belief. You just need to play with low risk, high win probability – just enough to win one of the next three points. This whole concept is where I like to say “Moneyball meets the Inner Game.”

Knowing the proper percentages to win points, games, and sets will win you matches. Your mindset dictates how you’re going to start playing the point. The same holds true for when you are down but that gets a bit more complicated. When you are down LOVE-40, then you need to win five of the next six points with the important caveat that you need to win three in a row to get to deuce. If you are down 15-40, then you need to win four of the remaining six points which includes the first two in a row as a necessity. Finally, when you are down 30-40, you must win three of the next four points including the first point as a must-win point.

This same metric holds true for the set score. If you are up five games to zero (5-0), then all you need is to win 20% of the remaining games or one of the next five to win the set 100% of the time. If you are up 5-1, then you just need to win one of the remaining four games of the set or 25% to close out the set 100% of the time. If up 5-2, then all you need to do is win 33% of the remaining points or one of the next three and you will win the set 100% of the time. Likewise, when you’re up 5-3, then you just need to win 50% or one of the next two games to win the set 100% of the time. If you are at 5-4 in the set, then you need to win two of the next three games or 67% of the remaining games to win the set 100% of the time (assuming you lost the first game). And finally, when you are at 5-5 you need to win two of the next three games (one “game” being the tiebreak) or 67% of the remaining games to win the set 100% of the time. This assumes nothing about player level.

Why is this so important? Because the human mind cannot maintain concentration for an entire tennis match. Knowing which points you need to really apply your focus on and also what to focus on at the beginning of these points will be critical to your success and a huge advantage for you. For example, taking risk when you are up for 40-0 would be unnecessary. Winning those games any less than 100% of the time would be unacceptable in my opinion. Knowing that you have to play in such a way that will win you 33% of the remaining points gives you the mindset to create a road map for victory.

If players think “I’m ahead, I have nothing to lose” then they will be sorely mistaken as you do have something to lose – the lead. When you are down is when you having nothing to lose as you will lose if you don’t change something. Current ATP Tour world #1 Novak Djokovic said “Tennis is a mental game. Everyone is fit, everyone hits great forehands and backhands.” I completely agree. Knowing what mindset to play with based on the game or set score is critical to your success.

I always welcome feedback at angeloarossetti @ gmail .com. The above content is proprietary. Please ask me for permission to reference or use in any way. I’m a proud Wilson Advisory Staff Member.

You can learn more about a couple of tennis GUINNESS WORLD RECORDS™ that I have been a part of:

Our Inspiration – 2 World Records 2 Minute Video
FOX News Story
MSNBC News Story
Inspirational Tennis Story: Tennis Begins with Love