Line Shading by Bookmakers
A bookmaker will sometimes apply a technique known as ‘line shading’ to squeeze additional money out of a contest by deciding on what the big favorites or ‘public’ team will be.
Public teams are popular teams wagered on by a large segment of the betting public. These may be teams with promising super-stars or very popular players or head coaches, or merely teams that are doing very well in the public’s eyes. Not all favorite teams will deserve the betting interest that they receive, but some will.
The bookmaker will look at each match-up individually and shade the odds line if applicable – basically when he feels he can get an edge.
Location can heavily influence the market in the form of betting volume from fans. Players from the East Coast might bet on the Patriots, Giants or other Eastern seaboard teams. Fans from the West Coast might prefer San Francisco or the Raiders, with bettors from the Chicago area jumping on the Bears.
The majority of these players won’t really care (in betting terms) how their team is doing, they just want to bet a few dollars on their team and have a bit of fun.
As an example, if a favorite football team should be ‘correctly’ priced at -6.5 on the spread / handicap – the bookmaker may want to ‘shade’ the line to -7. That half a point move puts the line out to a critical spread number and this could reap rewards for the sportsbook if the action floods in. Equally where the line -2.5 the book may try it on at -3, another crucial points spread number.
There are of course teams that the public dislike, so the opposite is true here. The line may get pushed out from e.g +5.5 to +7.5 on the unpopular team, especially if they are up against a warm favorite, thereby creating some possible value on the dog team.
Bettors can be notoriously changeable, teams that don’t perform well can hurriedly be discarded as a public team, just as quickly as they were embraced – this applies more to some teams than others.
The bookmaker needs to stay alert to these changes and if he employs a good balance of skill and judgement, he can profit well from these situations.
Some books are said to be able to increase their profit margins by over 20% if they get it right.