Originally Posted by
suicidekings
IMO, the spread is just not going to matter in this game. The books haven't taken a side, but rather set the line to balance action & minimize risk. The larger number of bettors playing GB on the spread (compared to the CHI spread) is being offset by a 60-40 split in favour of Chicago in plays on the ML. The net result is that the books are keeping opinion out of this game, and reading too heavily into the line will get you into trouble.
Given the following splits in betting (Sunday morning):
ML: GB = 40%, CHI = 60%
Spread: GB = 60%, CHI = 40%
At these ratios (and assuming an "average" bet size of 1u for simplicity), if you crunch the numbers for the books assets and liabilities for each possible outcome (1-GB win/cover, 2-CHI win/cover, 3-GB win/CHI cover), then the books stand to make the most from a Chicago outright win, followed by a split, and then the GB win/cover. The books will have calculated probabilities for these three outcomes and will do their best to balance the numbers such that they can hope for a Chicago win, but be aware that this is probably the least likely outcome and position themselves such that they won't stand to lose heavily if Green Bay wins/covers or the result splits.
This whole exercise becomes much more complicated when you start throwing in variable pricing, point buying, parlays, teasers, etc, but conceptually its just about the books calculating a net result for each of the three possible outcomes listed above from the hundreds/thousands of wagers that they're taking and positioning themselves to maximize their profit margin. Each wager is an entry into a spreadsheet and they all add up at the bottom. Not glamorous, but it is what it is...