Hi Phoenixxx!
Competitiveness? Well, the X and I met in Zoology class at University and studied for exams together. He got an A- and I got an A. Does that say anything about healthy competition between two people? competition only becomes an issue when people's Worth and Value hinges on winning...I used to enjoy a good competition now and then though I had to grow up a little bit to appreciate losing because nobody wins all the time.
One thing I noticed is that I began hating competition, even board games. I resisted competition to an unhealthy degree and perhaps that is also a result of the pathological relationship? It has taken a few years for me to even care about competition again...such as an art exhibit where heaven's knows, you're setting yourself up for direct criticism and failure if the goal is 'winning'.
I used to participate in debate (way back in high school when my narcissism was at an all-time high), led social groups both in education and community, and also directed a theater presentation or two. So when the X and I got into long debates over a variety of topics

, it didn't necessarily frighten me. But, those debates did change me.
How about yourself? Did you notice your attitude changing because of your X's reactions to losing or winning? (nobody likes being lorded over when they lose a hand of cards, right?)
Had I been more fearful of an aggressive argument (NOT physical battering), perhaps I'd have run the other direction much earlier. I still, even today, appreciate a healthy differing of opinions. If someone has a strong opinion different from my own, it usually broadens my mind---it certainly does NOT impact the way I feel towards them as a friend (or lover). But competition to me, was not necessarily about winning. This of course, is an attitude that grew up with me as I matured.
As far as 'outsmarting him' or 'giving it to him before leaving'? The thought never even occurred to me. Maybe I figured out early on that at some point, I'd stop myself...I dunno. It's an interesting idea to think about.
Hugs,
CZ