Success within a contest is held to raise the probability of further success beyond what the underlying skill implies.
Commentators identify momentum from streaks, and streaks occur in random sequences at rates people badly underestimate. Where careful work has looked, the measured effects have been small. The concept survives because it is applied after the fact, when the sequence is known.
In practice
- A team that scores twice is said to have momentum, and the same two goals in a loss are called a consolation.
- A run of four wins in twenty is unremarkable arithmetic and is narrated as a turning point.
- Possible explanations
- One explanation is psychological, that confidence and attention rise after success. Another is that streaks of the length people notice occur in random sequences, so the pattern is inferred from none.
- In its favour
- The psychological mechanism is plausible and there is some evidence for small effects in individual sports where opponents cannot adjust.
- Against it
- Studies find weak and inconsistent evidence, and much of what is called momentum is the clustering that random sequences produce, which commentators reliably underestimate.
- Standing
- Studies find weak and inconsistent evidence, and attribute much of what is called momentum to the clustering that random sequences produce. Related to the hot-hand debate, where the balance of evidence has shifted somewhat toward a small real effect.
- Subject
- Sport & Performance
- Essay
- The best-measured contests there are