user598: Apparently, when calculating a player's USCF rating difference after a win or loss, the K factor that is used is based on the player's rating. Now, I was always under the impression that two players with ratings a and b would play each other and that a difference in score is awarded to both of them such that their ratings after the match would be a+d and b-d (assuming player A won the match).
But let's say you have a player at 2075 (who would have a K factor of 32) and another player at 2125 (who would have a K factor of 24). Which K factor would be used? I could see a case for either of 32, 24, or even 28 being used in this case. What does USCF do here?

user1943: K-factor is used for each player individually. So, if one of them got 30 K-factor, his rating will change on the basis of that K-factor, while another player with 10 K-factor, for instance, will get rating on the basis of his own K-factor. 
There are Chess Rating Calculators on FIDE's official website. You can have a look: FIDE Rating Change Calculators

598: <p><a href="http://en.wikipedia.org/wiki/Elo_rating_system#Most_accurate_K-factor" rel="nofollow">Apparently</a>, when calculating a player's USCF rating difference after a win or loss, the K factor that is used is based on the player's rating. Now, I was always under the impression that two players with ratings <code>a</code> and <code>b</code> would play each other and that a difference in score is awarded to both of them such that their ratings after the match would be <code>a+d</code> and <code>b-d</code> (assuming player A won the match).</p>

<p>But let's say you have a player at 2075 (who would have a K factor of 32) and another player at 2125 (who would have a K factor of 24). Which K factor would be used? I could see a case for either of 32, 24, or even 28 being used in this case. What does USCF do here?</p>
 1943: <p>K-factor is used for each player individually. So, if one of them got 30 K-factor, his rating will change on the basis of that K-factor, while another player with 10 K-factor, for instance, will get rating on the basis of his own K-factor. </p>

<p>There are Chess Rating Calculators on FIDE's official website. You can have a look: <a href="http://ratings.fide.com/calculators.phtml" rel="nofollow">FIDE Rating Change Calculators</a></p>
