In the
1991 Super Bowl, as the
Buffalo Bills'
Scott Norwood attempted to kick the potential game-winning
field goal, members of the opposing
New York Giants could be seen
praying on the sideline. Obviously (and I believe they admitted as much after the game), they were praying for Norwood to miss.
God answered their prayers, I suppose, and Norwood barely missed the kick, and the Giants won.
This shows the inherent selfishness of thanking Jesus for victory -- because it's the same as thanking Jesus for making the other team lose. To me, prayer isn't ethical in zero-sum games.