"I think" and "In my opinion"

Students might notice I tend to cross out "I think" and "In my opinion" on essays.

I understand why they're used. Ask the average person on the Internet, and they will explain "I think" and "In my opinion" are used as a form of politeness when posting opinions on message boards.

They add nothing of significant value to the sentence though.

Think about this...

If someone at the racetrack came and said "I think No. 5 will win the next race," that would be an opinion right?

If someone at the racetrack came and said "No. 5 will win the next race," it would still be the same opinion!

At least, the second guy sounds confident in his thoughts. Also, by using "I think" and "In my opinion," the author is taking away attention from the actual topic and placing it on the author, which is a bit distracting.

So, try to minimize or eliminate altogether "I think" and "In my opinion."