Any sports fan knows that referees are as human as the rest of us – mistakes do creep in.

However, I recently read this short article citing studies that show ref’s also make more subtle, but systematic mistakes.

Home Crowd Advantage

This article discusses a study of 3500 Bundesliga matches that found measurable bias in favor of the home team:

• Interestingly the bias was more significant when there was no running track around the field – in other words when the fans were closer to the ref.
• Refs were shown footage of tackles with the sound on and the sound off. Those watching with the sound on ruled in favor of the home team 15.5% more often!

The Team in Red

In the past I have read that football teams wearing red win slightly more matches. This article discusses a study of tae kwon do referees found that they favor the fighter in red.

In tae kwon do one fighter has a red helmet and one has a blue helmet.

In the experiment 42 experienced refs were shown videos of sparring rounds.

• The red fighters were awarded on average 13% more points
• The videos were then digitally altered to switch the color of the helmets. Suddenly the points awarded flipped over with the new reds getting a bigger share.