In sports, a losing streak (a.k.a. a cold streak, losing skid, slide, schneid, or losing slump) is an uninterrupted string of contests (games, matches, etc.) lost by a team or individual. A losing streak is thus the opposite of a winning streak. A losing streak can last as few as two games, or it may last much longer.

A losing streak and a winless streak are distinctively different, as a winless streak may include:

1. tie games or draws
2. in first-class cricket, unfinished matches
3. in association football, ice hockey and some field hockey leagues where points are awarded for wins and drawn games, overtime or shootout losses if the draw at the end of regulation counts as a draw for points percentage.

Tie games can also be included in an unbeaten streak, as in soccer.

Most quantitative studies of winning and losing streaks, and the associated concept of psychological momentum, have failed to find any evidence that "streaks" actually exist, except as a matter of random chance.^[1] A team with low ability is more likely to lose frequently, and a team with high ability is more likely to win, but once ability is controlled for, there is no evidence that a "winning" or "losing" streak affects the result of the match.^[2] In fact, one study of European association football matches using a Monte Carlo methodology found that once ability was accounted for, a team was actually slightly less likely to win or lose when it had experienced the same result in the previous match.^[2]

Despite the apparent nonexistence of streaks in quantitative terms, many scholars in the field have pointed to the importance of understanding qualitative, psychological aspects of streaks.^[1] A series of losses can have a negative effect on team morale even if it has no direct effect on the outcome of the next game.^[3]

Studies in sports management suggest that some managers are able to interrupt losing streaks (and prolong winning streaks) through managerial strategies such as changing the lineup or rotation of players.^[4] Similarly, effective mental strategies may enable individual athletes to resist the psychological effects of a "losing streak" by staying focused on the task at hand.^[5] In team sports, effective strategies for combating negative momentum may include team cohesion activities and increasing the use of positive body language.^[6]

To the extent that they exist, losing streaks may arise from the loser effect: an increased probability of losing at time T, based on losing at time T−1, T−2, etc. This means that one has a slightly higher probability of losing the next match because one lost the previous one.^[7] The outcome of a match does not solely depend on the strength of the opponents, but also on how much effort one or the other is willing to invest. The loser effect rises from the tendency to hold back on the next match after losing. On the other hand, the winner effect encourages the opponent who won the previous match to invest more in the next fight. This phenomenon is well known in the study of animal behavior, where the winner and loser effects help to keep the level of conflicts low in group living animals.^[8]

List of the longest individual losing streaks of all time in each sport:

• List of Major League Baseball longest losing streaks
• List of National Basketball Association longest losing streaks
• Imperfect season
• Winning streak