The psychological (ab)use of timeouts in professional tennis

The (ab)use of timeouts as a tool for swinging momentum is a longstanding psychological question in tennis. We provided the first
real-world quantitative investigation of this, through an archival
analysis of bathroom timeouts taken between sets in professional
tennis matches [timeout N = 366 following stringent data preprocessing of confounds]. Our study revealed three key findings. First,
the majority of bathroom timeouts were taken by players who lost
the prior-set, suggesting that the decision to take a timeout is
triggered by negative momentum. Second, the likelihood of recovering from a lost set to win the next set was greater after
a bathroom timeout, relative to stringently controlled baseline
data where no timeouts were taken. Third, follow-up analyses on
the extent to which unforced-errors contributed to the forms of
points won and lost, indicated that the timeout advantage is
a combination of both the strategist benefitting from the opportunity to personally reset, and a disruption of the rhythm of the
opponent, rather than being disproportionally driven by one player.
Together, these pioneering findings uniquely inform players and
tennis governing bodies about the influence of timeouts and, more
broadly, elucidate the role that stoppages can play in sport for
altering momentum.