What does 'Out of left field' mean?

World of sports

• Across the board.

• At this stage in the game.

• Beat someone to the punch.

• (The) ball is in your court.

• Blind-sided.

• Blow the competition away.

• Call the shots.

• Change the game.

• Chip in.

• Come out swinging.

• Cry foul.

• Curveball.

• Down to the wire.

• Drop the ball.

• Face-off.

• Front runner.

• Full-court press.

• Get a head start.

• Get a second wind.

• Get into the full swing of things.

• Get off the hook.

• Get the ball rolling.

• Give it your best shot.

• Give one a run for one's money.

• (The) gloves are off.

• Go overboard.

• Go the distance.

• Go to bat for someone.

• Hands down.

• Hail Mary.

• Have someone in your corner.

• Have the upper hand.

• Heavy hitter.

• Heavyweight.

• Hit it out of the park.

• (The) home stretch.

• In the hole.

• In the same ballpark.

• In the same league.

• In the zone.

• Jump the gun.

• Keep one's eye on the ball.

• Keep the ball rolling.

• Knockout.

• Learn the ropes.

• Leave it all on the field.

• Level playing field.

• Lightweight.

• Long shot.

• Low blow.

• Make the cut.

• Neck and neck.

• No pain, no gain.

• No sweat.

• Not up to par.

• On target.

• On the ball.

• On the ropes.

• One-two punch.

• Out for the count.

• Out of left field.

• Out of bounds.

• Out of someone's league.

• Par for the course.

• Play by the rules.

• Play hardball.

• Plenty of other fish in the sea.

• Pull one's punches.

• Punt.

• Push it over the goal line.

• Put some points on the board.

• Race against time.

• Rope-a-dope.

• Roll with the punches.

• Run the gauntlet.

• Running on empty.

• Saved by the bell.

• Second wind.

• Settle a score with someone.

• Shot in the dark.

• Shoot yourself in the foot.

• Skate on thin ice.

• (A) slam dunk.

• Square off.

• Step up to the plate.

• Sucker punch.

• Swing for the fences.

• Take a back seat.

• Take a dive.

• Take a rain check.

• Take it on the chin.

• Take off the gloves.

• Take one's eye off the ball.

• Take sides.

• Take the bull by the horns.

• Take the wind out of one's sails.

• Throw a curveball.

• Throw in the towel.

• Throw one's hat into the ring.

• Time out.

• Three strikes and you're out.

• To be off base.

• Touch base.

• Turf war.

• Under the gun.

• (A) whole new ball game.

• Win hands down.

• Winning streak.

• Work out/workout.

• You can't win them all.

• Your call.