finding basebooks for specific sport

[onebet]

hello
My goal is to code a bot that will automate value betting. The coding itself shoudn't be the problem.
As far as I understood when valuebetting on asian markets different basebooks are neccessary so that I have a basebook for football for example.
My problem is now that I don't think that I have understood how to determin the most efficient bookmaker in a sport. I would try and use historical odds from bookmakers to look at their efficiency.
Is anyone nice enough to explain how I can see how efficient odds of a bookie are?
thank you

 

[scoresodds]

Use Betfair (exchange) as the line, its about as accurate as possible.