Example of a match rating calculation:
Team A's Current Score: 1500pt
Team B's Current Score: 1580pt
Team A's Chance of Winning: 1 / (1+10(1580 - 1500)/400) = 0.38686
Team B's Chance of Winning: 1 / (1+10(1500 - 1580)/400) = 0.61314
Now Let's say Team A won the battle then
Team A's New Score: 1500 + 32*(1 - 0.38686) = 1500 + 19.62 = 1519.62
Team B's New Score: 1580 + 32*(0 - 0.61314) = 1580 + (-19.62) = 1560.38
Now Let's say Team B won the battle then
Team A's New Score: 1500 + 32*(0 - 0.38686) = 1500 + (-12.38) = 1487.62
Team B's New Score: 1580 + 32*(1 - 0.61314) = 1580 + 12.38 = 1592.38
The K value used by Blizzard is 32. So each match, the maximum rating gain/loss will be 32pts. And if you play with a team with same rating, you will gain/lose exactly 16pts.
As you can see when a team with a higher ranking score wins a match against a lower ranking team, they receive fewer points than if the lower rank team won.