I almost always used to spar lefty even though I'm right handed and legged. Part of it was that I could get my right leg up faster and hit harder with it off the front than I could with my left, partially because it put people off.

The other thing was, I could land a NASTY inverted round which people who weren't used to me NEVER expected.

One time at a tournament as I was setting it up for a break, my instructor caught some of judges whispering amongst themselves "he'll never break it with that." He chuckled at them then said something like "you wanna bet?" to them.

I made the break on my first try.