Yep, so true. The thing about TDS ratings is that players aren't always playing at the rating they might have. An 8000 player could be playing worse than usual and a 7,500 player could be playing better than usual, which decreases the gap between their skill levels. If the 7500 player is able to win, then he might have performed at a higher relative skill level compared to the 8000 player that round. Luck also plays a role to some extent. Still, it mostly comes down to player performance. The win and loss results may describe the irregularities in each player's performance or the influence of luck.