Converting Odds to Moneyline?

[Nimirra]

Local book offers baseball in odds. For example, St Louis is 3 to 4.
What does a hundred dollar bet on St. Louis pay? What does a hundred dollar bet on Philly pay?

Is there an easy formula to convert it to a moneyline format in order to compare to online books?
Lastly, how do you figure his hold or vig?

 

[Boxslayer]

I could definitely be wrong but I would say 3:4 means for every 4 dollars you lay you are going to win 3. So, if you bet $400, you'll win $300. If you bet $40, you'll win $30.

I would convert this by dividing 4/3 = 1.33

Which I would say means that you have St. Louis at -133.

Which would make sense because if you bet $133, you'd win $100. If you bet $399(or $400), you'd win $300.

It's important to note if it is 3:4 or 4:3. 4:3 would now mean that you would win $4 for every $3 that you bet.
Once again, I could be wrong. I just look at games I like, cap them, and look at the line to see if there is value. I don't get all into it. I'm down with the K.I.S.S. method.