[BlitzTheBooks]

1)A majority of baseball lines open at 10 difference from a mirror odd (assuming this means dime line), ie Team A is -120, Team B +110. Team A is -145, Team B is +135, etc.

Why are some -240 and +220? Is this an example of a 20-cent opening line? Or is it just skewed b/c of a heavy favorite?

2)Is there a set ratio for lines? For example (at a dime line book), if a team is -120 is the underdog automatically a +110?

Throw a few points to someone for helping

[EXhoosier10]

You pretty much nailed it. As lines get further from -110/-100, you'll start to see 15, 20, and maybe 30 cent differences if the line gets to the -300 range.

Some books have 5 cent juice -102/-103, others are 8. -104/-104, others even -10, and some of the more recreational books have -110/-110. It's best to find the one with the lowest juice if possible. For that reason having multiple "outs" (sportsbooks) to choose from is ideal, if you are going to bet enough to get through rollover at all of them.