There are two map specific descriptive stats featured on match pages that need some explanation, Contest Score and Comeback Index.
Contest Score summarises how close the map was by reflecting how many rounds there were between teams throughout the duration of it. The figure is the average difference between the two team scores at any given time in the match. The lower the score, the closer the match.
The range isn’t specific, but any game where the average is below 2 is a fairly competitive game and it can be less than 1. A theoretical maximum is the average difference in rounds in a 16-0 slaughter, which would be roughly 8.
Comeback Index measures how large the swings between the two teams were during the match. It’s scored between 1 and 0, with 1 reflecting a game where one team got out to a 15-0 lead and the other came back to erase that advantage.
Note that comeback index doesn’t necessarily indicate that the comeback was successful or that any given advantage was completely erased, just that there was a big score discrepancy at one point that was made smaller, and if the comeback index score is closer to 1 then a lot smaller.