When I want to place a bet I oftentimes look at SBR, compare my options, And then usually take the best juice I can find. Many times the actual line will be different than what SBR is displaying. Not usually by a lot, maybe SBR will show -112 and the actual site will be -115. Does SBR query the sites repeatedly every few minutes or are the sites providing the lines willingly?
Sometimes, especially with bookmaker, The line will be bouncing back and forth on SBR but the line isn't changing at all at the site.
I'm not complaining. SBR is by far the best source for lines. I am just trying to get a sense of how the line information is gathered and updated.