No matter what the sport if you place a limit wager the house will ordinarily move the line one increment. The exceptions would be if the house already had nearly an equal amount of action on the other side of the proposition from an accumulation of smaller than limit size wagers, if the house had recently moved the spread due to an amount of wagers greater than the limit on the other side of the proposition, if the sportsbook manager or supervisor had a strong opinion on the game and chose to take a position on it (i.e. he believes the bettor is playing the wrong side) or if the player is a good customer of the house and asks if he can wager an amount larger than the limit on a particular game (casinos like to keep their high rollers happy).

Let's say you have a game that looks like this:

113 MINNESOTA BONSER +130

8.5OV

114 SEATTLE SILVA -140

Let's assume the sportsbook we are dealing with has a posted limit of $1000 (a "dime" in wiseguy terminology) on baseball sides. Ordinarily this means a bettor can wager $1000 on the underdog (Minnesota) or "to win $1000" on the favorite (Seattle). If a bettor wishes to make a limit wager on Seattle he would bet $1400 (to win $1000). The house would then (in most instances) move the line to Seattle -145 (with Minnesota at +135) and then the bettor would be free to play again. With his next bet he would have to wager $1450 to win that same $1000: the price has gone up.

It should be mentioned here that many betting parlors have taken to moving their baseball lines in one cent (penny) increments in response to betting action rather than the standard five cent (nickel) jumps that have been used for years. The basic reason behind that is still an attempt to find the balance point that will generate two-way action. The house uses the smaller incremental moves in an experimental fashion to find that balance point.

However, in this instance we're going to deal with a hypothetical sportsbook that moves its baseball line five cents following a limit wager. What this does to our player and other players (besides increasing the price for subsequent Seattle bettors) is to increase the percentage of winners needed to break even over the long run. And it decreases the chance of any subsequent Seattle bettors (those determined to play the Mariners despite taking the worst of it on the line move) coming out ahead over the same long run.

The percentage of winners needed to break even when laying 7-to-5 (-140) is 58.33%. When the odds increase to -145 (7 1/2-to-5 or 29-to-20) a player needs 59.18% winners to break even. That is an increase of .85% or actually 1.46% more winners than the player needed when laying 7-to-5 (-140).

At the -140 price our player needs 58.33% winners simply to break even so he ought to have determined through his handicapping methods that the Mariners really have at least a 60% chance of winning this game. That is, over the long run in the same situation with the same pitchers and the same lineups at the same site with the same injuries and same current form the Mariners would win at least six times out of every 10 games played so the true price on the game ought to be Mariners -150 or higher.

A 10-cent overlay when dealing with the favorite side of the equation does not leave the player much margin for error. If he's off a bit on his calculations and the Mariners are really only going to win 5.8 games out of every 10 played (58%) our player is going to wind up in the red rather than the black. So he might want to wait for a situation where he has a bigger edge, where his calculated probability of a team winning is significantly higher than the break even point of the posted price. For instance, had our handicapper's calculations led him to believe that the Mariners had a 65% chance of winning this encounter with the Twins then the true price on the game would have figured to be -185 rather than -145.

If we turn things around and look at them from the Minnesota side of the ledger we see that originally a Twins' backer would have received odds of 6 1/2-to-5 (+130 equals 6 1/2-to-5) but any Minnesota bettor playing after the line move caused by the limit wager on the Mariners will receive 6 3/4-to-5 (+135 or 27-to-20). Rather than 43.48% winners needed to break even at +130 our player will need only 42.55% winners to break even at +135, a decrease of .93% or, in actuality, nearly 2.1% fewer winners than at +130 (.93% being 2.1% of 43.48%).

Likewise, it might have happened that a limit wager was made on the Minnesota side of our sample game when the lines were first posted. Seeing this, the sportsbook would then lower the price on Seattle and the payoff on Minnesota by changing the line to Minnesota +125, Seattle -135. This would make it less expensive to bet Seattle (players would have to lay 6 3/4-to-5 or 27-to-20 rather than the original 7-to-5).

Meanwhile Minnesota backers who played after the line move would receive a lesser payoff of 6 1/4-to-5 rather than the original 6 1/2-to-5. That makes it more expensive to play Minnesota because it necessitates a larger wager to win the same amount of money. In theory this will "balance the books" for the house by attracting action on Seattle while at the same time discouraging further action on Minnesota.

It is impossible for the house to have balanced action on every game. At times the action remains one-sided even after a line move or two. At such times the house is all but admitting its initial price was a bad one. If it opens the Seattle game at -140 and moves it to -145 and then -150 what it is asking for is money at Minnesota +140 to cancel out the initial action on Seattle -140.

A line move can also discourage further play on one team without encouraging any on the other. When this happens the house has unbalanced action on a game or proposition and stands to lose money if the players prove to have the correct side. However, if the players prove to be wrong the house stands to win the one-sided action, making a larger profit on the single game than it would have if it was an ordinary game with balanced action. Therefore, if over the long run the house can have balanced action on the majority of its games while winning or breaking even on those games in which it is in jeopardy due to one-sided action then it will show a nice steady profit.

The house still employs limits and line moves in an attempt to balance the action on as many games as possible or to make those players looking to jump on the bandwagon of a game that has been deemed to be particularly attractive pay a premium for doing so. Thus when money shows or a limit wager is made on the Minnesota side of our sample game the house responds with the appropriate line move (from Minnesota +130 to Minnesota +125 and from Seattle -140 to Seattle -135).

What this does to the Minnesota side of the equation (besides lowering the expected payoff) is raise the percentage of winners needed to break even over the long run. The percentage of winners needed to break even when betting underdogs at 6 1/2-to-5 (+130) is 43.48%. However, when the potential payout is lowered to 6 1/4-to-5 (5-to-4 or +125) the percentage of winners needed to break even rises to 44.44%, an apparent increase of 96% more winners needed to reach the break even (almost one wager out of one hundred) but an actual increase of 2.2% more winners than at the previous price (.96% being 2.2% of 43.48%) or over two games per hundred. So the little things in the world of baseball handicapping do mean a lot.

The change or percentage of change from one increment to the next is more radical the lower the odds are to begin with. If the line is -180 (laying 9-to-5) then a change to -185 (laying 9 1/4-to-5 or 37-to-20) changes the percentage of winners needed to break even only from 64.29% to 64.91%, a change of only .62% or .96% more winners needed to break even. Likewise the change on the underdog side is not as radical as it only stands to reason that the higher the odds were to begin with the less difference a change of five cents on the line will make.

This is well worth remembering when wagering on baseball since the lines on baseball games can range from -105 (pick em, a price not shown on either of our charts but the player lays 5 1/4-to-5 or 21-to-20 no matter which side he wagers on and he needs 51.21% winners to break even) to -280 (14-to-5) or even higher on games involving strong teams with established pitchers versus poor teams with a marginal quality or totally unknown hurler on the mound.

It can be hazardous to one's bankroll to lay even an extra five cents on the money line with favorites in the lower price ranges because of the changes wrought in the percentage of winners needed to break even by such a change. If a line opens -115 and rises to -120 it may not seem like that big a deal but now 1.1% more winners are needed to just break even or, in actuality, 1.8% more winners than were needed at -115.

In the real world probabilities must always add to one or 100%: the chance of an event happening or not happening have to add to 100%. If the Rockies are playing the Giants the chance of the Rockies winning plus the chance of the Giants winning has to equal 100% (barring a rainout or suspended game which for wagering purposes don't count anyway). Due to the linemaker’s vigorish built into the line however the probabilities for posted lines will always add to greater than 100% with the percentage over and above 100% constituting the house edge.

Final wagering decisions must be based on more than simple line moves. It is mandatory to be able to make your own line (one that is superior to the oddsmaker's) in order to be a successful baseball handicapper. There is no shortage of sports handicappers who claim to be able to make a line "as good as" the linemaker's but there is no edge in making a line "as good as" the linemaker's: you must make one that is superior.

That is not to say that your line will always be superior to the oddsmaker's but when the two of you disagree your line must be superior in the majority of cases. That way you can back your opinions with confidence.

There will also be plenty of times (and there ought to be) when your number and the Las Vegas number agree (or are within five cents). At such times when a line move occurs consider going against the move even if all it gives you is a five-cent edge. If both the oddsmaker and you agree that the number on a certain game is such and such then there is a good chance of that being the right number and that makes any line move off that number highly suspect.

Baseball is heating up and so is Robert Ross! He's been releasing both side and total selections in the Grand Olde Game on a guaranteed basis: you win or you don't pay!