By Dr Victor Thompson
Clinical sports psychologist
Despite the science and multi-million pound budgets involved, superstitions or elaborate event rituals are alive and well at all levels in the world of sport.
Serena Williams's rituals include "tying her laces right"
Serena Williams, who plays in the final of Wimbledon this weekend, is no stranger to these rituals.
When asked why she had played so badly at the French Open last year, she said: "I didn't tie my laces right and I didn't bounce the ball five times and I didn't bring my shower sandals to the court with me.
"I didn't have my extra dress. I just knew it was fate; it wasn't going to happen."
So was it these objects? Well yes and no. It is her belief that she had missed taking something or doing something.
If you believe you are not going to do it, then you will be less confident and play in a less assured way. Performance suffers.
Andy Murray's coach Miles Maclagan apparently insists that Andy uses the same practice court, at the same time, every day.
Close observers of his game at Wimbledon will also have picked up that when Andy wins a point during his service game, he insists that he gets the very same ball back to use the next time.
Now, can that ball really be different to any of the other balls opened at the same time, on the court, from the same manufacturer? I doubt it.
These routines can develop for sportsmen and women in two different ways.
Andy Murray uses the same ball when he wins a point during his service
The first is that when the athlete has a better than expected outcome, they understandably search for the reason behind it so they can repeat the good result.
They will latch onto something, almost anything.
So instead of concluding that it was due to their good training or simply that they had been leading up to this performance, they incorrectly conclude that it was because they wore something different, spoke to someone different, watched some TV programme or listened to a particular piece of music.
The second is if they perform poorly they attribute this to the absence of something. Was it that they forgot to wear something or do something?
Or if they did follow their routine, was it that they followed it differently, too quickly, too slowly, or started it too early in the day?
So with time, routines become more elaborate, strange, removed from normality, and 'superstitious-like'.
Why do superstitions remain over time if they have nothing to do with the outcome?
Sports people need to do well, to feel confident, to manage stress, anxiety and uncertainty. Because they think their extreme routines can at least partly influence the outcome... then they better keep following them.
Not to do this, they reason, would simply be foolish. In other words, they follow their routine 'just in case'.
(Breaks in routines)... can create anger, stress, anxiety and physical tension
But there are some obvious problems with having deeply-held routines or superstitions.
When things get in the way of you following your routine - perhaps you cannot find your lucky shirt or underpants, someone else needs to be that last person out of the changing room, or your music player breaks so you cannot listen to your lucky pre-game album - this can create anger, stress, anxiety, and physical tension.
It becomes a distraction and causes a drop in confidence... all of which leads to a higher chance of performing poorly.
Also, if you are attributing your good or bad performance to these strange things, then you will not be looking at the real performance factors that could raise your games, for example strategy, skills, nutrition, confidence and focus.
And performing your set routines or superstitions can actually get in the way of a good performance and be a major distraction.
So, what can be done to help athletes with these deeply-held routines?
I work with athletes to have flexibility in their pre-event, warm-up and during the competition routines.
They can learn to cope easily without their lucky underpants, favourite music or practice scenario. To remain confident in their performance, good at responding to change and fine with uncertainty.
I advise them to sit back and let their opponent unravel when external events get in the way and to capitalise on these times.
It has got to be better to attribute success to what you do, rather than how you put on your clothes half an hour before a match.