What is in a Line Change?

Many new gamblers fail to grasp the fact that not all line changes are equal in the world of wagering. For example, is a movement from -105 to -110 equivalent to a move from -205 to -210?

In short…No, but let’s delve a little deeper.

We already know that wagering lines can be converted into percentage terms. That is, we can determine from a line what the public perceives as the percentage chance that a given fighter will win.

For example, let’s start with -105, a line just barely over even money. At -105, the public believes that the fight will be close, and that a given fighter has a 51.22% chance of walking away with a victory.

Now lets look at the slightly higher line of -110. It is still very close to even, but it now represents a 52.38% chance of a given fighter winning. A 5 cent change in the line produces a more than 1% change in a fighter’s odds of winning.


Let’s do the same with the other two lines. First we have -205, which correlates to a 67.21% chance of a fighter winning. If we increase the line by again, just 5 cents, we get -210. That correlates to a 67.74% chance of winning. As you can see when you look at the difference of the two odds, it is less than 1%. In fact, it is .53%, or almost half of the percentage change that we saw when moving from -105 to -110.

This may not seem like a huge amount, but it gets much more pronounced the higher a line moves away from even. For example, take -505 to -510, which is 83.47% and 83.61% respectfully. Now a 5 cent change in the line represents only a .137% change in the chances of a fighter winning. There is a premium the higher the lines go.

Another way of looking at this characteristic of line changes is to look at it graphically. Below is a simple graph showing favorite lines and their corresponding percentage odds.

As you can see, the slope of the line gets steeper the closer it is to even money (-100). What this means for gamblers is that small changes in the line near even money, corresponds to large percentage changes in the odds of a fighter winning. This is also evident when looking at underdogs, as the following chart shows:

The farther a line moves from even (either -100 or +100), the more of a premium a gambler has to pay for a corresponding percentage change of a fighters odds.

You may also notice that the line will never become horizontal to either 0% or 100%. It will just keep getting closer to it for infinity. For example, a line -1,000,000 is still not a sure bet since it corresponds to a percentage odd of winning of 99.99000099990000….% (it just keeps going and going).

Now, we know that when you look at a line and see it move from -105 to -110, you don’t think it is a huge movement. However, when a line moves from -500 to -550, it looks far larger. Yet, from -105 to -110 is a 1.16% move in a fighters odds, while a line movement of -500 to -550 is a 1.28% increase in a fighters odds.

Always keep this in mind about line changes. You should be much more excited about small drops near even money, than you are about much larger movements on heavy favorites or underdogs. To mitigate any adverse psychological effects on your gambling decisions, always convert lines into percentages to see where the edges really are. Luckily, you can do that easily with our Line Converting Calculator.

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