Are you left-handed?

Yesterday over lunch, my friend told me he is ambidextrous i.e. he can use both of his hands for writing. I was amazed at this and he told me that he used to write with his left hand when we was young and his parents forced him to write with his right hand. It does not matter really if someone is right handed or left handed. However, for a sportsman being left handed can be an added advantage. Let’s access how?

Research shows that 90% of the people are right handed are 10% are left handed. Assuming that the same holds true for sports in general as well. For sports like boxing, tennis, cricket, wrestling, badminton etc. where there is direct contact with the opponent or the mode of delivery has a significant impact; being left handed can really pay off. Practice is an essential part for any sportsperson. If one is left-handed, he/she will have most of the practices with right handed players (remember 10% left-handers). Thus the left-handers will be better equipped to face right-handers since they have played/practiced with them in the nets/ training sessions.

On the other hand, right handed players get to practice more with right handed players (90% players) and thus are more adept with right handed opponents. Thus, both left handed and right handed players are better off playing against right handed opponents (based on practice and training).

Hence, if a right-hander faces a left-hander, the left-hander has an advantage since the usual right handed payer has not had much practice against left-handed opponents. A left-hander when plays against a left-hander has no competitive advantage (both lack practice against each other); same is the case when a right-hander meets a right-hander (both have adequate practice against each other). But when one of those 10% left-handers plays against one of those 90% right-handers, it is likely to favor the left-handed player. Might be the same reason explains how Nadal overpowers Federer so often. Something definitely to ponder or rather research upon!?
PS: Generalized assumptions made to draw out conclusions.
PPS: I am right handed.