Why do the sportsbooks switch sides on totals?

[mister bee]

Hey all,

i know this a newbie question, but i just start betting totals. when the books publish their overnight lines, say dodgers over 9 -115, then the next morning it's under 9 -115, is this because everyone hammered the over and the books want action on the under? if not what else is the reason for the books switching sides.

thanks,
mister bee

[Willie Bee]

Are we related? Welcome to SBR

Are you saying the Under was at +105 or thereabouts in the opener? Assuming there was not a pitching change, or info regarding a key batter or two that will be missing from the lineup, then it probably is from early wagers hitting the Under.

[mister bee]

Are we related? Welcome to SBR

thanks for the welcome willie bee. we may be related on my mother's father's brother's side, from the old country of course!

Are you saying the Under was at +105 or thereabouts in the opener? Assuming there was not a pitching change, or info regarding a key batter or two that will be missing from the lineup, then it probably is from early wagers hitting the Under.

so going with your logic: a lot of early wagers on the under, so the books switch sides and charge -115 or greater, and if people are still betting the under the they jack up the line and then start adding 1/2 points, right?