user16389: Doesn't it create bias for the country?
Disclaimer: I realize that benefits of having more teams from the same country far outweigh possible drawbacks, just trying to reason how possibly "unfair" can this be for the other teams, and / if this can be improved.
Imagine last decisive round where two teams from the same country are paired between each other. Will it be a fair match? Does it make sense to avoid such pairings?

user12629: There is a tradeoff between making the pairings that "should" be made according to the strict pairing rules, and attempting to prevent collusion.  Imagine this scenario:
Russia 1: 8.5
Russia 2: 8
India:    8
Peru:     7.5

Which is more unfair: to have Russia 1 play Russia 2 and have a possible prearranged result, or to prevent Russia 1 and Russia 2 from competing, causing Russia 2 to play a team with a lower score instead of the strong Russia 1 team?
There are several ways to handle this.  You could switch the pairings only when it does not cause a team to be moved up or down a pairing group. You could switch the pairings in any round except the last two. Or you could not switch them, and watch closely for signs that the players aren't playing seriously.

16389: <p>Doesn't it create bias for the country?</p>

<p><strong>Disclaimer</strong>: I realize that benefits of having more teams from the same country far outweigh possible drawbacks, just trying to reason how possibly "unfair" can this be for the other teams, and / if this can be improved.</p>

<p>Imagine last decisive round where two teams from the same country are paired between each other. Will it be a fair match? Does it make sense to avoid such pairings?</p>
 12629: <p>There is a tradeoff between making the pairings that "should" be made according to the strict pairing rules, and attempting to prevent collusion.  Imagine this scenario:</p>

<pre><code>Russia 1: 8.5
Russia 2: 8
India:    8
Peru:     7.5
</code></pre>

<p>Which is more unfair: to have Russia 1 play Russia 2 and have a possible prearranged result, or to <em>prevent</em> Russia 1 and Russia 2 from competing, causing Russia 2 to play a team with a lower score instead of the strong Russia 1 team?</p>

<p>There are several ways to handle this.  You could switch the pairings only when it does not cause a team to be moved up or down a pairing group. You could switch the pairings in any round except the last two. Or you could not switch them, and watch closely for signs that the players aren't playing seriously.</p>
