What These Numbers Mean

The "spread score" is an indication of the average difference relative to the spread, as opposed to the median one. 50 is average - it means my system believes Vegas is right on target. Anything above 50 indicates that the team will on average do better than the spread; anything below means they will do worse. In practice, there's really only a significant difference below 52 and above 48. Most games where the actual result was quite different from the spread have had scores above 52 here. This is best explained by an example.

Let's say Boston is playing at Philadelphia. Philadelphia is a two-point favorite. My "ATS cover odds" indicate that Vegas has gotten it right - there's a 50% chance that either team will cover the spread. On the other hand, Philadelphia has a score of 52. This would mean that if the teams were to play 100 times, I'd expect that (1) each would cover the spread about 50% of the time, but (2) Philly would on average win by more than two points. In other words, this is a game where there's a pretty good chance of a Philly blowout win, or a Boston close win (or one point loss).

In practice, the home team will more often show up with a high score. That means that there's a decent chance that the game will get out of hand, and the road team will get blown out. Sometimes this is accompanied by a high "ATS cover odds" number, but not always.