Many negotiators find an approach, a methodology, a suite of behaviours that works for them, and stick to them. Why wouldn't you?

Well, because it makes you predictable, that's why.

Here's what Rafa Nadal does before a match:

• He has a freezing cold shower 45 minutes before the match.
• He wears both socks at the same height.
• He always places his bottles in the same exact position.
• He carries one racket onto the court, and five rackets in his bag.
• He ensures his opponent crosses the net before he does during a changeover.
• He places his hair behind his ear and fiddles with his shorts or underwear before each serve.
• He sips his energy drink and then his water, always in the same order.
• He uses a towel after every single point.
• He never rises from his seat before his opponent.
• He avoids walking on the sidelines.
• He doesn't put his headband on until just before he enters the court.

Critically, these behaviours empower Nadal, as he feels that he is in control. It is true that the other party can predict Nadal's actions exactly. But when he comes to serve? Well, he is harder to read, and that is what counts.

When you negotiate, by all means adopt preparatory routines that make you feel empowered or in the zone (Nadal's explanation for the cold shower). But don't be predictable, as the second or third time the other party encounters you, they will be watching for patterns or repeating behaviours.

This article explores AI analysis of three top tennis players, Nadal, Djokovic and Federer in order to predict their next shot:

"It needs about three matches to figure out a player's style. Once it has got those three matches it is pretty solid," Denman said. The algorithm was mimicking the brains of the top players who were already trying to predict their opponent's next shot.

So in three matches, the AI algorithm can predict a player's next shot!

While the artificial intelligent system proved successful, its biggest challenge was the unpredictability of the "Greatest Of All Time" player.

Be like Roger. Be unpredictable.

"We had an analysis of how accurate it is for those three top players -- Djokovic, Nadal and Federer," Denman said. "And it was least accurate for Federer, who is perhaps the most versatile. It struggled the most to predict him. He can do anything, so the model was more often wrong about him," he said.

In this 90 second Fast Idea, I explore how we can behave in the first 90 seconds of meeting someone in order to make a great first impression