Quote:
Originally Posted by TomCowley
Your Korobov result doesn't make sense if you're just using rating differentials and not some kind of player-specific results with colors or skewing the tiebreaks way more to the favorite than the classical games, which would seem odd.
The key is my draw rate that I'm using. Solely on rating differential, Nakamura should score 59.2% against Korobov. Therefore I assumed that Nakamura will win the mini-match 59.2% of the time, and also that if it goes to tiebreaks, Nakamura will win the tiebreaks 59.2% of the time.
After the draw, we now have one classical game left, with Korobov as white. I use a value of white being worth 40 ELO points, so in that one game, Korobov's expectation is a bit better. Specifically he should score 46.1% (rather than just 40.8%). Since I assume that 55.8% of games are drawn (based on results so far in the tournament), this means that Korobov should win tomorrow 18.2% of the time, and Nakamura should win 26% of the time, with a 55.8% chance that it goes to tiebreaks.
Therefore IF there is a decisive game tomorrow, there is a 58.8% chance that it goes in Naka's favor. And if there is NOT a decisive game, then we go to tiebreaks, which go in Naka's favor 59.2% of the time. It's coincidence that Naka outrates Korobov by just the right amount, to where Naka's winning odds with black (excluding draws) line up so perfectly with his overall score expectation (including draws).
So there is a skew for color, but there is not any sort of player-specific skew.
Edit: The one other factor is that I did update the live ratings mid-way through the calculations, and the 0.8 rating point gain for Korobov, and corresponding drop for Naka, does affect the numbers at the tenth-of-a-percent level. It has nothing to do with why the odds are *essentially* unchanged, though, that's as described above.
Last edited by BobJoeJim; 08-20-2013 at 02:59 PM.