Definition
A contrarian play is a bet or DFS pick that goes against the most popular choice. In betting, it means backing a side the market or public is avoiding. In DFS, it means using a player with low projected roster percentage to create a different lineup.
There is no special contrarian-play formula. The math still comes from price and probability. For American odds of -110, implied probability is:
110 / (110 + 100) = 52.38%
A contrarian play only has value if your true win probability is higher than the break-even probability.
Worked Example
A sportsbook lists Team A at -110 and Team B at -110. Public tickets are heavily on Team A, but your projection gives Team B a 55% chance to win.
At -110, a $110 bet wins $100. The break-even rate is 52.38%. Your projected edge is:
55.00% - 52.38% = 2.62 percentage points
Team B is contrarian because it is unpopular, and it has betting value because your projection clears the price.
Why It Matters
Contrarian plays help when public popularity pushes attention toward one side while the price still favors the other. The concept is useful only when low popularity is paired with a real projection edge.